Which statement best explains how power is generated in a tidal power plant?

a. a barrage releases water as the tide comes in and goes out, turning the plant's turbines.

b. as the water flows through a barrage at high and low tides, it turns the plant's turbines.

c. a barrage holds water at high tide, when the water is released, it turns the plant's turbines.

d. a barrage holds water back when the tides change, the force of this turns the plant's turbines.