within three generations. over a long period of time. when a species is overpopulated. when there are abundant resources.
I gave my students this multiple choice question: Two different species evolving from a common ancestor most likely occurs

Only one answer is correct among these 4 choices:
- within three generations.
- over a long period of time.
- when a species is overpopulated.
- when there are abundant resources.

Could you tell me which one is correct?

over a long period of time.