单项选择题

According to the text, if a person never forgot ______.
A) his ability to learn would be improved C) he would survive best
B) he would have a lot of trouble D) the evolution of memory would stop

A.According to the text, if a person never forgot ______.
B.his ability to learn would be improved
C.he would have a lot of trouble
D.he would survive best
E.the evolution of memory would stop