in that paragraph, the expression Mounting evidence could be a bit confusing, but it indicates that there's been reaserch about it before, and that it all points in the same direction, the more research proving the same point means the data is convincing. The answer is D.
The answer would be <em><u>A</u></em>. The words mounting evidence in this case suggest that the<em><u> data is highly convincing.</u></em>
Explanation:
"Mounting evidence" are words to describe a growing body of evidence, however, in this instance this is use to reinforce the fact that there's a lot of evidence that supports the author's idea. Therefore, this would give the words "mounting evidence" the meaning of something highly convincing.