Planners in City X noticed that many of the trees in the city were dying because of exposure to increased levels of air and water pollution. A study they commissioned revealed that sycamore trees actually thrive in environments with elevated levels of carbon monoxide, the main pollutant emitted by automobiles. In order to reverse the trend of dying trees, the city adopted a policy to replace all sick trees with sycamore trees.
Which of the following, if true, would most weaken the logic employed by the city planners?
In the forest, oak trees live an average of 70 years while sycamore trees only live for an average of 50 years.
Automobile manufacturers are developing newer car models that emit significantly fewer pollutants.
A survey by Urban Forests found that the sycamore is the most common tree in American cities.
The city recently installed low exhaust buses for its public transportation system.
Sycamore trees are extremely sensitive to sulfur dioxide, the main component of acid rain.
As the article indicates "Sycamore trees actually thrive in environments with elevated levels of carbon monoxide, the main pollutant emitted by automobiles" Why then would B or D be inaccurate? If the premise is that the trees will thrive due to elevated carbon dioxide levels and the plan is to replace sick trees with living trees, wouldn't a drop in carbon dioxide pollution affect the newly planted sycamore trees? I can see the merits of E, but don't see why B and D are not correct.
[Show/hide explanation]
Correct Choice: (E)
The conclusion is a plan: replace sick trees with sycamores, which thrive in the presence of carbon monoxide. In order to weaken an argument whose conclusion centers on a plan, we'll look for an answer choice that shows why the plan, on its own terms, won't work. Choice (A) is an irrelevant comparison; whether oak trees live longer than do sycamores has no impact on the success or failure of the city's plan. Choices (B) and (D) are out of scope; the city's plan concerns the resistance of trees to carbon monoxide, not the potential lower level of carbon monoxide in the future. Choice (C) is irrelevant. Choice (E) provides information that suggests that the city's plan won't work: while sycamores thrive in environments with elevated levels of carbon monoxide, they are extremely sensitive to another pollutant that exists in City X. (E) is therefore the credited answer.
Which of the following, if true, would most weaken the logic employed by the city planners?
In the forest, oak trees live an average of 70 years while sycamore trees only live for an average of 50 years.
Automobile manufacturers are developing newer car models that emit significantly fewer pollutants.
A survey by Urban Forests found that the sycamore is the most common tree in American cities.
The city recently installed low exhaust buses for its public transportation system.
Sycamore trees are extremely sensitive to sulfur dioxide, the main component of acid rain.
As the article indicates "Sycamore trees actually thrive in environments with elevated levels of carbon monoxide, the main pollutant emitted by automobiles" Why then would B or D be inaccurate? If the premise is that the trees will thrive due to elevated carbon dioxide levels and the plan is to replace sick trees with living trees, wouldn't a drop in carbon dioxide pollution affect the newly planted sycamore trees? I can see the merits of E, but don't see why B and D are not correct.
[Show/hide explanation]
Correct Choice: (E)
The conclusion is a plan: replace sick trees with sycamores, which thrive in the presence of carbon monoxide. In order to weaken an argument whose conclusion centers on a plan, we'll look for an answer choice that shows why the plan, on its own terms, won't work. Choice (A) is an irrelevant comparison; whether oak trees live longer than do sycamores has no impact on the success or failure of the city's plan. Choices (B) and (D) are out of scope; the city's plan concerns the resistance of trees to carbon monoxide, not the potential lower level of carbon monoxide in the future. Choice (C) is irrelevant. Choice (E) provides information that suggests that the city's plan won't work: while sycamores thrive in environments with elevated levels of carbon monoxide, they are extremely sensitive to another pollutant that exists in City X. (E) is therefore the credited answer.
