A disadvantage of using hydroelectric power is:
a. It severely pollutes the water it is built on.
b. collecting enough wind to turn the turbines.
c. the disruption of the river ecosystem.
d. the emission of air pollution.
Hydroelectric power doesn't pollute water or add anything to it, it doesn't use wind for its operation, and it doesn't emit anything into the air. It does, however, disrupt the river ecosystem.
