formation of the supercontinent Pangea intense volcanic activity cooler temperatures rising sea levels
I gave my students this multiple choice question: Which event most likely allowed for the explosion of mammal diversity that occurred during the Cretaceous period?

Only one answer is correct among these 4 choices:
- formation of the supercontinent Pangea
- intense volcanic activity
- cooler temperatures
- rising sea levels

Could you tell me which one is correct?

cooler temperatures