GMAT Reading Comprehension (RC) | Re: Research data indicate that there is a great deal of poverty

Hey guys, about the third question, why it is not C ?
It is quite clear with A, but I'm not satisfied.

In the passage:
"Some economists believe that rigorous enforcement of existing equal pay laws would substantially decrease this wage inequity.............................Since gender concentration exists......, other economists argue that a comparable worth standard , which..............., should be applied instead."