2. GWD-23-Q23

After several years of rapid growth, the healthy care company became one of the largest health care providers in the metropolitan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals.

A.      while it then proved unable to handle the increase in business, falling months behind in its payment to

B.      while it then proved unable to handle the increase in business and fell months behind in its payment to

C.      but then it proved unable to handle the increase in business, falling months behind in its paying

D.      but then proving unable to handle the increase in business, falling months behind in paying

E.       but then proved unable to handle the increase in business, falling months behind in paying

 是在搞不懂，为什么要选E呢？两个谓语并列，中间可以加逗号吗？

GOOD

in its paying和in paying有什么区别呢？

C中的it是可有可无吗，还是一定要省略，公用主语呢？

求NN们给点回答吧