The correct answer is B) by providing more labor resources.
Empire-building benefited farm production by providing more labor resources.
Empire-building allowed the Emperors to expand their territories conquering new lands and having more servants to serve the king. This also meant having more labor resources, more hands ready to work in the farm fields to grow more crops, to produce more food for the empíre and trading purposes. Better crops and food production meant more trade, and more trade translated into more income and resources for the empire.