The concept of "duty ethics" states that
选项：

A:the rightness of an action is determined by eva lluating the pros and cons of its consequences.
B: the rightness of an action is determined by existing law s and contemporary social standards that define what is right and wrong and where the line is.
C:the rightness of an action is based on the custom s and norms of a particular society or community.D the rightness of an action is based on one's conscience and moral standards.