This question asks for the attitude of the author in a specific paragraph.
Considering line 49-52 and 57-60, the author is positive on the further implication of the possibility in selective treatment with further discoveries. Anything that cites non-positive attitude should be eliminated, so let's eliminate C) - "apprehension", D) -"concern", and E) - "Skepticism."
As for A), possible benefits, it seems, are already realized, and that’s how the author explains them (57-60).
Thus, the answer to this question is B) from 49-52 and 57-60.