Of the three variants of the underlined portion of the sentence below, which is the best and why?  I'm trying to help my high school junior improve her grammar skills, but I'm stumped by the problem below.  The correct answer is given as "C."  While "C" seems fine to me, I don't understand why "B" is deficient.  My daughter's workbook notes that "B" is not parallel; however, I thought that in seeking to determine whether parallel structure exists in a sentence, one need not pay attention to items that modify the elements that are equal in placement, importance and/or function.  Thus, regarding choice "B," I don't think that it matters that "its educational" modifies "quality," but that "effectiveness" has no modifier.  Thank you for your help.

Many changes occurred while she was president of the college, and they increased its educational quality as well as effectiveness.

A)  college, and they increased its educational quality as well as effectiveness
B)  college; these changes increased its educational quality and effectiveness
C)  college; these changes increased both the educational quality and effectiveness of the college To join or leave this LISTSERV list, please visit the list's web interface at: http://listserv.muohio.edu/archives/ateg.html and select "Join or leave the list"

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