How might a surplus of food have helped civilizations advance from hunter gatherer societies

B.A surplus of food allowed people to specialize in different jobs.

Explanation:

A surplus of food is definitely something that allowed people to specialize in different Jobs. This is how we can say that the people in the past used this surplus. I hope this works for you.

a, c, & d are correct:

they wanted lands to settle the extra population.

they wanted new markets for english goods.

they wanted to avoid civil war.

c, they united with once