Answer:
B) They selectively planted seeds of plants they could eat and used stone tools to harvest the crop.
I hope this helps :)
Step-by-step explanation:
One possible way that might have occurred is that farmers harvested wheat after it was ripe, but before it self-dispersed, thereby collecting only the wheat that was still attached to the plant. By planting those seeds the next season, the farmers were perpetuating plants that had later-breaking rachises.