Which Client Statement Reflects an Understanding of Circadian Rhythms

Which client statement reflects an understanding of circadian rhythms?

A) "When I dream about my mother's horrible train accident, I become hysterical."
B) "I get really irritable during my menstrual cycle."
C) "I'm a morning person. I get my best work done before noon."
D) "Every February, I tend to experience periods of sadness."