GWD-8-18求助

之前的讨论帖子未能回答我的问题

所以另开贴

请各位牛人赐教

Q18: According to a recent study of consumer spending on prescription
medications, increases in the sales of the 50 drugs that were
advertised most heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came from sales of the 9,850 prescription medicines that companies did not advertise or advertised very little.

A. heavily accounts for almost half of the $20.8
billion increase in drug spending last year, the remainder of which
came

B. heavily were what accounted for almost half of the
$20.8 billion increase in drug spending last year; the remainder of the
increase coming

C. heavily accounted for almost half of the $20.8
billion increase in drug spending last year, the remainder of the
increase coming

D. heavily, accounting for almost half of the $20.8
billion increase in drug spending last year, while the remainder of the
increase came

E. heavily, which accounted for almost half of the
$20.8 billion increase in drug spending last year, with the
remainder of it coming

答案是C，请问D为什么错

有人说D，E都是sentence fragment

我对这点概念很模糊

D答案 heavily, accounting for almost half of the $20.8
billion increase in drug spending last year,这半句没有谓语啊！

E答案也是，缺谓语，句子结构不完整！