Which is an example of a direct quotation?

A. According to my research, Zeus was instrumental in starting and ending the entire Trojan War.
B. Greek scholars agree that Zeus frequently changed form so that he could influence others.
C. Dr. W. Wharton explains, “Zeus was the king of the gods, ruler of sky, weather, law, and fate.”
D. Artists usually portray Zeus as a strong man with a dark beard, a lightning bolt, and scepter.