The answer is B I think...
Egyptian slaves were used to build them
The use of mechanized farming techniques is well suited to geographic areas that c. have large expanses of flat land. Regions such as the Canadian Prairies is a large expanse of flat land and as such easily supports mechanization in planting crops such as wheat. Mechanization in agriculture would be hampered in areas that experience frequent flooding as equipment could get stuck in mud or suffer other water damage.
Answer:
The cold currents often form when the air on the subtropical high blows over a cold mass of water, then the cold air is dragged to the equator. Warm currents, on the other hand, are large masses of warm water moving further away from the equator, at higher temperatures.