According to the passage, which of the following is true concerning the cultural ermination of emotions

A． Emotional expression varies between individuals to a significantly greater extent than it does between cultures.
B． Neither anthropologists nor Darwinists have successfully established a scientific method for comparing one emotion with another.
C． The cause of the emotion may vary from one historical time or geographical place to another.
D． It is impossible to say whether any given emotion is in fact an emotion, or merely a biological response.
E． It is difficult to distinguish between culturally-acquired emotions and innate ones determined by biology.