Answer:
The correct answer is option a. "The populations will evolve separately from each other".
Step-by-step explanation:
Two squirrel populations that have very little gene flow will not share their genetic adaptations to survive the changing environmental conditions that they can face. Therefore, it is very likely that the two populations will evolve separately from each other. This contrasts with species that evolve collectively since they share their genetic adaptions due to a high gene flow among them.