The primary function of the final paragraph of the passage is to:
Lend support to one of the points that the author makes in his book.
The reviewer opens the last but one paragraph by mentioning that the author makes two 'timely' points. So he agrees to these two points of Professor Ferguson. The last paragraph is about the second point, i.e. the important role played by finance in human progress.
Option B seems to be close but remember that this paragraph is not about financial crisis and the positive developments that may have happened during or after it. It is about how Ferguson sees finance as playing an important role to facilitate human progress.