People may have chosen to become sedimentary because
1)surplus food meant others could learn different jobs
2)plows were easier to make than spears
3)farming created surplus crops to survive winter
4)large groups were safer
5)large department stores emerged
People may have chosen to become *sedentary* because "3) farming created surplus crops to survive winter," since this was one of the most significant factors in the development of civilizations (the food surplus).