How did agriculture begin? Capturing and tending animals.
Collecting seeds from plants.
Sowing specific plants that would attract desired prey animals.
Caring for plants that were growing already.

Im going to say B, since a and c dont really involve agriculture, but it might be d. I choose b since taking care of plants that already growing doesn't really allow you to keep growing that plant and making farms. However, for be, you would be able to keep growing plants to makes to make food over and over again, allowing you to have surpluses and farms :) hope this helps