Here's the
official explanation provided by the GMAC for this question:
This sentence refers to a difficulty (or difficulties) that savings banks face as a result of federal restrictions. The original version suggests that there may be some relationship between the difficulties and the fact that the banks compete with unregulated investment vehicles. However, this wording is uninformative and puzzling in that it does not clearly indicate what the difficulties are or why they are mentioned in relation to the competition. Furthermore, the singular verb
has does not agree with the plural subject
restrictions.
Option A: The singular verb
has does not agree with the plural subject
restrictions. The wording is indirect and ambiguous. It could beintended to mean that the restrictions have made it difficult for savings banks to compete with the unregulated investment vehicles or that the restrictions have caused some unspecified difficulties for the savings banks. On either interpretation, with this wording,
as can have two different meanings:
during the time that or
because.
Option B: The singular verb
has does not agree with the plural subject
restrictions. The wording does not clearly indicate whether the difficulties are related to the banks' competition with unregulated investment vehicles.
Option C: This wording is indirect and ambiguous. It could be intended to mean that the restrictions have made it difficult for savings banks to compete with the unregulated investment vehicles or that the restrictions have caused some unspecified difficulties for the savings banks. On either interpretation, with this wording,
as can have two different meanings:
during the time that or
because.
Option D: Correct. The verbs all agree with their subjects. The wording is clear, concise, and direct and uses the correct idiomatic form
make it difficult for X to do Y.
Option E: This wording is indirect and ambiguous. It could be intended to mean that the restrictions have made it difficult for savings banks to compete with the unregulated investment vehicles or that the restrictions have caused some unspecified difficulties for the savings banks. On either interpretation, with this wording,
as can have two different meanings:
during the time that or
because.
The correct answer is D.
Please note that I'm not the author of this explanation. I'm just posting it here since I believe it can help the community.