Why might a surplus food supply contribute to the development of cities?

A. More food allows people to hunt more.

B. More food allows the population to move from place to place.

C. More food allows people to control their source of water.

D. More food allows the population to grow.

I believe the correct answer is D. more food allows the population to grow.

A is incorrect because if there's a surplus of food, it means people don't have to hunt as much as they used to. B is also incorrect because more food means a more permanent settlement. C is incorrect because the two things aren't connected. And D should be correct because if there is a lot of food, it means that the population can grow and everyone can be fed.