Which effect of long-term environmental change is the driving force behind evolution? adaptation extinction migration speciation

The correct answer is adaptation.  

Adaptation is the process which animals and plants go through biological changes to conform to their environment  over time. In adaptation, they evolve in order to survive. Not to be confused with natural selection, which is defined as organisms (already adapted to their environment) that tend to survive and produce more offspring.

The Answer is Adaptation

Explanation:

It is adaptation because adaptation is when animals adjust to the environment.