What effect did agricultural tools have on the development of cities?
A
Agricultural tools could be used to dig holes for house building.
B
Agricultural tools allowed early humans to grow a surplus of food, thus freeing up time to build settlements that grew into cities.
C
Agricultural tools needed to be made by an expert. Humans gathered near the expert and settlements developed.
D
Settlements developed so humans would not have to travel far to trade their agricultural tools.
