问到语法题

miguel29

8.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
这里为什么要用less啊？从哪个词看出来的，我本来以为是cost所以我用lower了

eshopaholic

one percent of $541 billion = 5.41billion -- a number

less than a number

miguel29

谢谢。。。搞定