Of the Following Examples, Who Is LEAST Likely to Use

Of the following examples, who is LEAST likely to use contraception?

A) Antoine, whose girlfriend is the same age he is.
B) Marsha, who has a good relationship with her boyfriend, and has regular conversations with him about contraception.
C) Rita, who is involved with a man six years older than she is.
D) Carla, whose family stresses the importance of personal responsibility for behavior.