Which solution would local farms if the water level in a reservoir used for irrigation became low?

a. build chinampas to raise the farmland.
b. build wind-powered pumps to use groundwater.
c. use shadufs to dig out the reservoir.
d. turn farmland into paddies.

B. Build wind-powered pumps to use groundwater.

Could be a useful way.

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.