Which of the Following Individuals Is in Kohlberg's Social Contract

Which of the following individuals is in Kohlberg's social contract stage of moral reasoning?

A) Dorothy does what the teacher says because he knows if he doesn't he'll be punished.
B) Bonnie obeys the teacher because she wants the teacher to like her and to think nice things of her.
C) Casey obeys the teacher because she understands that the only way that a classroom and a school can run effectively is if all of the students behave appropriately.
D) David obeys the teacher because the rules say that all students must obey, and as a student his duty is to obey the rules.