C is the best answer, but A is the most frequent mistake. People see "zoo" and assume it must rhyme with "moo." But adding "-ology" to something makes it "the study of," and you have to pronounce the "-ology" part without blending the o into the prefix. All the choices besides C list "zoo" as the first syllable, which is incorrect. There ARE some sources that give nods to the pronunciation listed in A, but always with the explanation that "zoh-OL-uh-gee" is "more correct." In fact, "zoo" is short for "zoological garden."