Why not E?

I'm in the same boat, picking D but not really knowing what's wrong with E. Could you please explain? Thanks!

@Karry-Jiao and @richmlw, Great questions. Let's take a look at (D) and (E). (E) says, "describing a flaw in the reasoning on which the original conclusion was based" (E) is a tricky answer. The problem with it is that the passage's author does not describe the flawed reasoning that led to the original conclusion. If the author had done this, she would have mentioned how the original conclusion makes the jump from correlation to causation. However, the author merely points to an alternative explanation, so (E) is out. (D) says, "providing an alternative hypothesis to explain the data on which the original conclusion was based" The alternative hypothesis is that the proposed caused and proposed effect are actually flipped, so (E) does a great job in discussing how the author counters the original conclusion. (E) is the correct answer. Hope this helps. Let us know if you have any other questions!