What Can Be Said About Economists in General

What can be said about economists in general?

A) they do not try to explain people's tastes, but do try to explain what happens when tastes change.
B) they must be able to explain people's tastes to explain what happens when tastes change.
C) they do not believe that people's tastes determine demand and therefore ignore the subject of tastes.
D) they believe that tastes and demand move in opposite directions.