[求助]大全688

688.        The American Medical Association has argued that the rapidly rising costs associated with malpractice litigation are driving doctors from the profession and that reform of the tort system is imperative for bringing malpractice insurance premiums under control.

(A) that reform of the tort system is imperative for bringing malpractice insurance premiums

(B) that reform of the tort system is imperative if malpractice insurance premiums are to be brought

(C) that reform of the tort system is imperative to bring malpractice insurance premiums

(D) reform of the tort system is necessary in bringing malpractice insurance premiums（C）

(E) the tort system needs to be reformed so that malpractice insurance premiums are brought

答案是 c, 能解释一下吗？

句子主干：

the AMA has argued that......and that.........