I am confused about the usage of variously in option C.
In option B, is the use of functioning in a stiffled manner wrong.
I chose the right answer but that'e because these did not look right to me. Can;t exactly figure out what's wrong with them though.
In B, the wording you referenced is certainly not ideal; I believe that it would be labeled by the GMAT test writers as "awkward and wordy". B also is a run-on sentence, which consists of two independent clauses which are joined but a comma rather than a semicolon. There is more discussion in this thread: sc-during-the-past-decade-the-labor-market-in-france-t5227.html
For C, tell us more about your question regarding "variously". Thanks!