A misplaced modifier is a word, phrase, or clause that is improperly separated from the word it modifies / describes. Because of the separation, sentences with this error often sound awkward, ridiculous, or confusing. Furthermore, they can be downright illogical.
The answer is C. Women are not adequately represented in U.S. monuments. “‘Why not continue Bly's work, she thought, by bringing visibility to some of these women so rarely depicted in public sculpture?’”