Help, XDF-s5-13 rate of v.s. rate for

isuffering

13. State officials report that soaring rates of liability insurance have risen to force cutbacks in the operations of everything from local governments and school districts to day-care centers and recreational facilities.
(A) rates of liability insurance have risen to force
(B) rates of liability insurance are a force for
(C) rates for liability insurance are forcing
(D) rises in liability insurance rates are forcing
(E) liability insurance rates have risen to force

I know the answer should be C

but i can't tell the difference between the meaning of the phrases" rates of liability insurance" and " rates for liability insurance" if thee's any.


And  I want to know the difference  between "rate of " v.s. "rate for" concerning the meaning, and usage  of the two phrases.

Can any NN help?

Thanks in advance.

isuffering

anyway, thanks

tongxun

Actually, I do not find out any difference between these two phrase. But I suppose that there be somewhat different between of and for. That's all.