Can anyone explain why E is NOT the answer and D is?
I think I see why D is the answer - The assumption in the argument is that newspapers choose their stories based on how dramatic they are and thus, in order to explain the higher frequency in appearance, the argument concludes small obs. studies must be more likely to be dramatic. Ans D demonstrates this flawed logic by providing an alternative explanation - the fact that observational studies are more frequent is only an accurate representation of the sample size, in which small obs. studies are more common.
But I'm still not sure I understand why E is not correct... Doesn't the argument assume that being dramatic is a cause of whether a study is chosen to be reported it on? And couldn't it be possible that the findings sounding dramatic are simply an effect OF being reported on (since the news tends to dramatize/sensationalize anyways)?