Answer:
Climate change, Availability of resources
Explanation:
1. Soon enough when the climate on the planet started to become more arid and become too hot, so humans started to migrate from Africa.
2. People started to move away to the places where resources were available.
The act of identifying relationships between two or more events in history is The Dawes Act
There are 3 correct answers to this questions, which are A, B and C. D is incorrect.