Hi @BMoore, thanks for your question. The chief indications of Passage B's "pointed skepticism" come from lines 36-42 and again in lines 59-65, although honestly the tone of skepticism is pervasive throughout.
Essentially, the author of Passage B is criticizing the argument in Passage A by pointing out what that argument overlooks and takes for granted.
This is a good question on which to use process of elimination if you are having a hard time. Hopefully, it is apparent that the author of Passage B is not in any kind of agreement with the author of Passage A, which helps you eliminate (a) and (b). Nor is he neutral, eliminating (c). Ambivalence would mean a more wishy washy position, and yet the tone of Passage B does come across as critical. That should, hopefully, get you to answer (e).
