Am not clear with the explanations provided hence, reopening this post..
IMO . E strengthens the conclusion. C is neutral and the rest weaken, since this is all weaken excpet question went for the one that strengthens. Please clarify why E os incorrect here
The new drug Prozac and the old one Elavil are about equally effective in treating various forms of depression, although patients on the newer drug may have slightly fewer side effects. Thus, revenue from the sale of the new drug is going to far exceed the revenue from the sale of the old drug.
All of the following statements weaken the conclusion of the argument above, EXCEPT:
(A) Elavil is also used as a powerful anti-emetic medicine.
(B) The Drug Control Authorities in six states have refused to allow the sale of Prozac till some more tests are carried out.
(C) Some side effects of Elavil are common to Prozac as well.
(D) Prozac is not recommended as an anti-depressant for diabetics and heart patients.
(E) The unit sale price of Elavil is higher than that of Prozac.