Which of the following best describes Immanuel Kant's categorical imperative?
选项：

A: If an action cannot be taken repeatedly, then it is not right to be taken at any time.
B: One should take the action that produces the least harm or incurs the least cost.
C: One can put values in rank order and understand the consequences of various courses ofAction.
D: If an action is not right for everyone to take, it is not right for anyone to take.
E: You should act towards others as you would like them to act towards you.