The argument summarized:

A study shows that chiropractics helped people with back pain. Therefore, to decrease the amount of people with back pain we should focus on those who have back pain.

When you summarize the argument it should become obvious that the critical assumption to the argument is;

Chiropractics cannot be used to prevent back pain before it starts. This is what C states in a more complicated manner.

If you would like, you can negate this and see if it defeats the argument. If the negated version defeats the argument, the original version is an assumption of the argument;

Chiropractics can be used to prevent back pain before it starts.

If you this is true could the author possible come to their conclusion? Absolutely not. If people can use chiropractics to stop ensure back problems will not develop, then you should not just focus on those who have back pain now.


(A) is not the answer because its irrelevant whether people may benefit from other treatments. We are focused on chiropractics in this discussion.

(B) is not the answer because were not concerned in this argument with how it is getting paid for. We are concerned in this argument with what the effects of chiropractics may be.

(D) is not the answer because even though using it over a long period of time may be more effective, in this argument we want to know if it is only beneficial to those people with back pain.

(E) is not the answer because it is irrelevant. The fact that people miss work days because of back pain has no baring on this particular argument.

Hope this helps.

Thanks,

Jared

The Ergonomic Society conducted a study that indicated that many people develop severe back problems during adulthood, and that virtually all such people who received chiropractic treatment showed great improvement. Therefore, in order to minimize the proportion of the population that suffers from back pain, the Ergonomic Society recommended that chiropractic treatment be directed toward those adults who suffer from severe back problems.

Which of the following is an assumption on which the argument depends?

The conclusion is - "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"
Premise
1. many people develop severe back problems during adulthood
2. virtually all such people who received chiropractic treatment showed great improvement
-----------------------------------------
A) Any person who receives chiropractic treatment for back pain may also benefit from other forms of treatment.
irrelevant .
B) Large insurance carriers cover chiropractic care for back problems to a lesser degree than they do other medical treatments. irrelevant
C) Individuals who receive chiropractic or other treatment prior to developing severe back problems are not less likely to develop back pain than those who do not.
This is the best of the avaialble options. Though I must agree that while I was reading the argument , I mentally had phrased an assumption that people develop back problems only in Childhood and not before that
D) Chiropractic treatment is more effective in treating severe back problems when utilized over a long period of time, as opposed to sporadically. irrelevant
E) Severe back pain and other problems often cause individuals to miss workdays.irrelevant