Answer:
High crop yields on fertile flood plains permitted more people to pursue non-farming activities
Step-by-step explanation:
The developmentof farming in the first river valley civilizations (Ancient Egypt, Mesopotamia, India and China) led to the development of more complex economies, where some people could puruse non-farming activiest, although the vast majority of people continued to be farmers.
Among these who practiced non-farming activities were: professional soldieres, accountants, merchants, priests, and politicians.