Which Type of Generating Plant Would You Expect to Be

Which type of generating plant would you expect to be more energy efficient, steam- electric or hydroelectric?

A) Hydroelectric, because it is not a heat engine and so is not restricted by the second law of thermodynamics.
B) Steam- electric, because there is so much more energy per ton in fossil fuels than in water behind a dam.
C) Hydroelectric, because the lake and river water provides natural cooling for the exhaust.
D) Steam- electric, because it can have a very high operating temperature due to having a large and thick boiler.
E) Hydroelectric, because there is so much energy in a large lake raised up behind a dam.