Which of the Following Best Illustrates the First Law of Thermodynamics

Which of the following best illustrates the first law of thermodynamics by Niagara Falls?

A) Water at the top of the falls has high kinetic energy; as the water moves over the waterfall, its kinetic energy is converted into potential energy; when the water reaches the bottom of the waterfall, its potential energy is transformed into other types of energy: heat, sound, and mechanical energy.
B) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into other types of energy: heat, sound, and mechanical energy.
C) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into potential energy again.
D) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is lost.