By observing the behavior of animals, scientists may be able to ______.

A．there are as many advantages to being poor as there are to being rich
B．being rich can bring more problems than being poor
C．rich children can be deprived of the thing they are most in need of
D．wealth brings more disadvantages than advantages to rich children

A．should learn to know how normal people lead their lives
B．have too much money to spend
C．have more troubles than common people do
D．may not feel deeply satisfied with what they achieved