1. One of Arthur Jessop’s first acts as president of the FHA was to deny a request from the private sector that federal home loan programs should be expanded to cover houses not conforming to civil construction codes.

(A) should be expanded to cover houses not conforming to

(B) be expanded to cover houses not conforming to

(C) should be expand to cover houses not conforming with

(D) would have been expanded to cover houses not conforming to（B）

(E) had to be expanded to cover houses not conforming with

why "conforming " here use the form"ing" , what does it mean? and what is the other use for the word?