Hydro electric power is the process of production of electricity from the mechanical energy of water.
In the process of generation of hydro electricity ,large dams are constructed in which the water is stored.The water present at top of the dam has potential energy.The water is driven downward with high pressure. During the falling of water,the potential energy of the water is converted into equivalent kinetic energy. The water coming down with a heavy speed is allowed to fall on a turbine which is connected to a generator.
The mechanical energy of water drives the turbine and electricity is generated due to the electromagnetic induction .
Hence the option A is right i.e falling water that turns the turbine.
