Which of the Following Best Captures Kant's Reason for Thinking

Multiple Choice

Which of the following best captures Kant's reason for thinking that the categorical imperative requires treating rational beings as ends in themselves?

A) It is a universal psychological law of humanity that each individual regards himself or herself as unconditionally valuable, and so acting on universal laws requires treating people as ends in themselves.
B) All other ends that an imperative might tell you to pursue are ends for you only if you have particular inclinations, but you necessarily regard your own rational nature as an end in itself, as does every other rational being.
C) Most ends are pursued for the sake of something else, as a job is pursued for the sake of money, but each person pursues his or her own happiness for its own sake, making humanity an end in itself.
D) Everyone recognizes that others will treat them with respect if they treat others with respect, leading everyone to acknowledge everyone else as ends in themselves to be treated with respect themselves.