Which of the following best explains how food surpluses led to the growth of populations? (1 point)

a
People had enough food, so they would not go hungry.

b
A food surplus meant that in years with bad harvests, people still had food to eat.

c
With a steady supply of food year in and year out, people felt safe having more children.

d
Farmers could use some of the grain they harvested for seed to grow more grain.