Federally imposed restrictions on how much they may pay small savers has made difficulties for savings banks as they are competing with such unregulated investment vehicles as money market certificates.

(A) has made difficulties for savings banks as they are competing with such

(B) has made difficulties for savings banks competing with such

(C) have made difficulties for savings banks as they are competing with

(D) have made it difficult for savings banks to compete with such

(E) have made it difficult for savings banks as they are competing with such

OA D

Source: Princeton Review