Consider an Engineer Who Decides Not to Overcharge His Client

Consider an engineer who decides not to overcharge his client even though he could get away with it because he does not want to risk developing a reputation for dishonesty. Kant might consider this decision not to overcharge the client as an example of a(n)

A) act that conforms to the demands of duty but which is not from a respect for duty.
B) act done from a universalizable maxim.
C) act that maximizes consequences.
D) example of psychological egoism.