Critical Reasoning

The economy around Lake Paqua depends on fishing of the lake's landlocked salmon population. In recent years, scarcity of food for salmon there has caused a decline in both the number and the size of the adult salmon in the lake. As a result, the region's revenues from salmon fishing have declined significantly. To remedy this situation, officials plan to introduce shrimp, which can serve as a food source for adult salmon, into Lake Paqua.
Which of the following, if true, most seriously calls into question the plan's chances for success?
A. Salmon is not a popular food among residents of the Lake Paqua region.
B. Tourists coming to fish for sport generate more income for residents of the Lake Paqua region than does commercial fishing.
C. The shrimp to be introduced into Lake Paqua are of a variety that is too small to be harvested for human consumption.
D. The primary food for both shrimp and juvenile salmon is plankton, which is not abundant in Lake Paqua.
E. Fishing regulations prohibit people from keeping any salmon they have caught in Lake Paqua that are smaller than a certain minimum size

OA [spoiler]D
Plz explain why D is correct[/spoiler]

The argument assumes that introducing shrimp into the lake will provide more food for the adult salmon, so the salmon population can increase in number and size. But if D were true, and both shrimp and juvenile salmon ate plankton, then the shrimp would actually be competing with the juvenile salmon for food. In that case, the juvenile salmon might never make it to adulthood, because there wouldn't be enough food for them; the argument says that plankton is "not abundant" already. The shrimp wouldn't end up being a food source; they'd instead cause further decline in the salmon population by further reducing the already scarce supply of food.

I was asked by PM to comment, so here goes.

The economy around Lake Paqua depends on fishing of the lake's landlocked salmon population. In recent years, scarcity of food for salmon there has caused a decline in both the number and the size of the adult salmon in the lake. As a result, the region's revenues from salmon fishing have declined significantly. To remedy this situation, officials plan to introduce shrimp, which can serve as a food source for adult salmon, into Lake Paqua.

Goal: To stop the decline in revenues from salmon fishing by helping the salmon to stay alive.
Plan: To introduce shrimp into the lake.
Assumption: That the plan will work. That the shrimp will help the salmon. (Also, notice that the passage talks only about the adult salmon. What about the poor baby salmon? If all the baby salmon die off, ultimately there will be no salmon left for the fisherman to fish.)

Predict: The correct answer will show how introducing shrimp into the lake won't help the salmon and therefore won't stop the decline in revenues from salmon fishing.

Which of the following, if true, most seriously calls into question the plan's chances for success?

A. Salmon is not a popular food among residents of the Lake Paqua region. Who cares where the revenues come from? The fish could still be sold to other people. We know that there have been revenues from salmon fishing because they've been declining. Those revenues must be coming from somewhere.

B. Tourists coming to fish for sport generate more income for residents of the Lake Paqua region than does commercial fishing. Out of scope. The passage is concerned only with the revenues from salmon fishing.

C. The shrimp to be introduced into Lake Paqua are of a variety that is too small to be harvested for human consumption. Out of scope. The argument isn't about humans consuming the shrimp. The purpose of the shrimp is to feed the salmon.

D. The primary food for both shrimp and juvenile salmon is plankton, which is not abundant in Lake Paqua. Correct. This answer choice says that the shrimp and the juvenile salmon will be competing for the same scarce food source. If the shrimp can't feed on the plankton, the shrimp will die, and the adult salmon will have nothing to eat. If the juvenile salmon can't feed on the plankton, they too will die, and the population of salmon will die out. So introducing the shrimp isn't going to help the salmon, and revenues will continue to decline.

E. Fishing regulations prohibit people from keeping any salmon they have caught in Lake Paqua that are smaller than a certain minimum size. Out of scope. The argument isn't about what kinds of salmon can be kept after they're caught. This answer choice doesn't tell us anything about the shrimp.

The correct answer is D.

Hope this helps!

Recieved a PM to answer this - unfortunatley my answer is pretty similar to the above, I hope it adds something.

This is an argument that follows the pattern of problem and solution - the problem is the salmon population is declining becuase the food for salmon is declining. The solution is to add shrimp to the lake so the salmon can eat it.

The assumption is always that the plan will work and not create any additional problems.

to weaken this we have to find a way to say that the plan will not work, or that the plan will create additional problems.

A. this isn't about fishing salmon nor is it about shrimp (the solution)
B. Again Tourists is too far outside the subject and doesn't involve shrimp
C. They aren't for human consumption and the passage says the salmon can eat them.
D. This is the right answer because if the Shrimp have no food then the salmon cannot eat them for very long - they will die from lack of food, and the baby salmon will die too becuase there is no food for them.
E. Again, this isn't about the solution of adding shrimp.

The economy around Lake Paqua depends on fishing of the lake's landlocked salmon population. In recent years, scarcity of food for salmon there has caused a decline in both the number and the size of the adult salmon in the lake. As a result, the region's revenues from salmon fishing have declined significantly. To remedy this situation, officials plan to introduce shrimp, which can serve as a food source for adult salmon, into Lake Paqua.


Which of the following, if true, most seriously calls into question the plan's chances for success?


This is a weaken question..So attack the conclusion..or show that the cause does not help the effect...


A. Salmon is not a popular food among residents of the Lake Paqua region.
So what..may be they are all export oriented units.


B. Tourists coming to fish for sport generate more income for residents of the Lake Paqua region than does commercial fishing.
strenghtens

C. The shrimp to be introduced into Lake Paqua are of a variety that is too small to be harvested for human consumption.
Shell answer choice..we are talking about shrimp or salmon

D. The primary food for both shrimp and juvenile salmon is plankton, which is not abundant in Lake Paqua.
hmm..this is a keeper..i will come back to this..

cREAM OF THE CRAP...
beST answer choice


E. Fishing regulations prohibit people from keeping any salmon they have caught in Lake Paqua that are smaller than a certain minimum size
again ..Out of context Going back to D

I also got PM'd to reply, which is actually pretty annoying, especially since the PM was just a link to this post in the subject line and no details about what your question is.

Please don't make a post and then PM every expert around to get someone to respond - make your post, see what replies you get, and THEN if you still need help PM one expert who can help you out.

for salmon to survive they need food.
let us assume it is shrimp. but shrimp shd also get food to stay alive. they eat plankton but less planktosn are there in lake
juvenile salmon also eat plankton majorily.there will be competition for food already in short supply

D

jainrahul1985 wrote:The economy around Lake Paqua depends on fishing of the lake's landlocked salmon population. In recent years, scarcity of food for salmon there has caused a decline in both the number and the size of the adult salmon in the lake. As a result, the region's revenues from salmon fishing have declined significantly. To remedy this situation, officials plan to introduce shrimp, which can serve as a food source for adult salmon, into Lake Paqua.
Which of the following, if true, most seriously calls into question the plan's chances for success?
A. Salmon is not a popular food among residents of the Lake Paqua region.
B. Tourists coming to fish for sport generate more income for residents of the Lake Paqua region than does commercial fishing.
C. The shrimp to be introduced into Lake Paqua are of a variety that is too small to be harvested for human consumption.
D. The primary food for both shrimp and juvenile salmon is plankton, which is not abundant in Lake Paqua.
E. Fishing regulations prohibit people from keeping any salmon they have caught in Lake Paqua that are smaller than a certain minimum size

OA [spoiler]D
Plz explain why D is correct[/spoiler]

All the explanations above are so exhaustive and helpful.

We need to weakent the success of the plan...arg assumes that by increasing the number of shrimp would cause decline the salmon population....choice D weakens this assumption very well....if shrimp and juvenile salmon depend on plankton for their food and that plankton population is not enough then the success of the plan would be weakened....

HTH!

Cheers!