大全一题

1.        Even though the direct costs of malpractice disputes amounts to a sum lower than one percent of the $541 billion the nation spent on health care last year, doctors say fear of lawsuits plays major role in health-care inflation.

(A) amounts to a sum lower

(B) amounts to less

(C) amounted to less

(D) amounted to lower（C）

(E) amounted to a lower sum

请问这里dispute 是什么词性？为什么选c 好心人帮忙解释一下

thanks