d. warmer climate that followed the ice age made it easier to plant and raise crops.
Explanation:
Women discovered agriculture basically by accident. It is told that they would spread seeds and, once they returned to a place where seeds were spread and found out that new crops were growing. Combining that finding with the climate change (which provided longer growing seasons and drier land), and the fact that the populations were growing, the need of new sources of food, the new findings about the seeds and the new temperature all caused the transition.
