Answer: A. Learning to domesticate plants and animals changed the way humans lived.
Step-by-step explanation:
A cause and effect relationship is one that shows that something changed as a result of a stimuli/ actions/ series of action.
The stimuli/ actions/ series of action here is humans learning to domesticate plants and animals.
The effect is that humans were able to settle down and develop complex societies which means that their way of life was changed as a result of them learning agriculture.