Need Help with this 700 + level CR from Manhattan practice t

many people deveope back pain during adulthood
chiropractic traement reduce the develpment of back pain


so imo C is correct assumption

IMO C

I would say that while C was not my best choice, A,B,D, and E were definitely not an assumption.

A, B D E are looking irrelevant.

But I could find how C is the assumption.

Can somebody explain it with the negation test.

This is what PowerScore called defender assumption. Consider the below casual relationship

Chiropractic treatment (cause) --> Improvement in severe back problem ( effect) [ which is also a conclusion]

To defend this casual relationship, the author is saying in C that the reverse is not true i.e. the back problem has not been caused by any previous chiropractic treatment. If C is not true, then people got back problem from the previous chiropractive treatment and hence the author's conclusion fails.

Thaanks Vishal.

It looks a horrible problem : misleading language

Actually I feel that this is quiet a simple problem.
But the real issue is the language of the problem.

If you read the argument again, then unnecessarily the author is flipping between 'back pain' and "severe back pain"

If we replace "severe back pain" with "back pain" in this problem, then I think it will be easy to understand.

You are right. And that's why C was not my first choice but C is the least worst of all choices.

The conclusion of the argument would be - to minimize the proportion of the population that suffers from back pain, ....... chiropractic treatment be directed toward those adults who suffer from severe back problems.

We need to keep two things in mind. First, ask the question 'Is the given answer choice necessary for the argument?" If the answer is yes, we make it a contender. Second, apply the negation test on the contenders.

A – Not necessary for the argument.
B – Irrespective of coverage if chiropractic care is required it will most probably be recommended by the society. Hence do not consider.
C – Hmm ......confusing and interesting let’s keep for further study. I have not fully dissected it but this looks relevant to the argument. I could have spent time fully figuring this out, but I realized that it is important enough to keep and revisit, this saves time since I can check out the other choices with which this choice should compete.
D – Out of scope. The argument is about applying chiropractic treatment and not how long it must be applied. Hence do not keep.
E – That is bad but does nothing for the argument. Hence leave out.

Thus we have eliminated all except C and even without analysis we have our answer. However, let us try to see how C makes sense.

Apply the negation test (Negation should weaken the argument):
C - Negation of C: Remove 'not' - Individuals who receive chiropractic or other treatment prior to developing severe back problems are less likely to develop back pain than those who do not.
Does this weaken the conclusion? Yes, if providing chiropractic or other treatment prior to development of backpain helps decrease the incidence of back pain, the proportion of population developing back pain would be less, the Society should have recommended chiropractic treatment for all adults not just those suffering from severe back pain.

Hence pick C

Hope this helps.