GMAT Critical Reasoning (CR) | Re: The new drug Prozac and the old one Elavil are about equally

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