Society as a whole was advanced by agriculture. Land that is farmed can support more than 50 times the number of people that same land can support through subsistence (bare necessities) living. Because of agriculture, a standing armies developed among the stronger societies. b great forests in North Africa were destroyed. c hunter-gatherers were able to buy food from neighbors. d the building of cities was delayed by 1000 years.
Because of agriculture "a standing armies developed among the stronger societies". This is because farmers could take care of food issues while others fought.