Kant Would Say That When a Car Dealer Charges Honest

Kant would say that when a car dealer charges honest prices, the action has moral worth if the man does it because

A) doing so would created the best consequences both for him and for his customers.
B) he would feel guilty if he cheated customers.
C) he feels a sense of love and sympathy for his customers.
D) he could not rationally make dishonesty into a universal law.