I thought A) was correct but I changed my mind to D) because the passage states that, "Approximately 80% of the participants in each group reported a significant relief." This means that the drug did not really have an effect. If it did, they would claim something like "80% the group ...

I was a bit stumped on this question... I came down to B) and C) and ended up choosing B). It was mainly an issue of time reference. In the stimulus, Party X has been recently accused and Party Y was involved in a scandal 3 years ago. In answer choice C), the plaintiff engaged in the illegal actions...