Why Did the Practice of Settled Agriculture Lead to the Emergence

Why did the practice of settled agriculture lead to the emergence of more complex civilizations?

A) People practicing settled agriculture needed a more structured political system.
B) People with a steady supply of food were free to devote their energy to accumulating wealth, producing art, and creating ceremonies and rituals.
C) An increase in the number of children in such societies gave rise to the educational institutions associated with complex civilizations.
D) Property owners in such societies demanded laws and institutions that protected their property rights.