Which option best exemplifies what Rachels means by saying that ethical egoism is "unacceptably arbitrary?"
A) Ethical egoism rests on the morally irrelevant distinction between pyschology and philosophy.
B) Ethical egoism rests on the morally irrelevant distinction between races, e.g., African American and Caucasion.
C) Ethical egoism shares the same problems as psychological egoism, and therefore the distinction between the two is arbitrary.
D) Ethical egoism rests on the morally irrelevant distinction between self and others, such that the former is placed in a wholly different moral category from the latter.