The Benefits Within Moral Standards Are Best Seen in Which

The benefits within moral standards are best seen in which statement?

A) There is a complete list of adequacy criteria for moral judgments that philosophers all agree on.
B) Professional codes are the rules that are supposed to govern the conduct of members of a given profession.
C) Professional codes of ethics provide a complete and reliable guide to one's moral obligations.
D) People who are exclusively concerned with their own interests tend to have happier and more satisfying lives than those whose desires extend beyond themselves.