og 101

101. 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 a 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

我开始以为dispute 是个动词，查了字典是个名词，表示“不同意”，但我看不懂原文了，怎么解释原句？

the word 'dispute' can be used as not only verb but also noun.

the verb in this sentence - Even though the direct costs of malpractice disputes amounted to less than one percent of the $541 billion the nation spent on health care last year - is 'amounted'.