[A]: Basis of adaptation is the preexisting gene mutation.
[R]: In changed environment, a hidden gene mutation may express and result in survival of the organisms and finally lead to adapta- tion to new conditions.
A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false
