I'm not a dreamer!

Elvis, who is smoking above, is one of those who have a mania for perpetual motion machine. Perpetual motion describes motion that continues indefinitely without any external source of energy. The yellow boat in the photo is the latest version of his invention (just an idea yet). His main idea is that the boat sucks in the sea water and absorbs energy from it to acquire propulsion, releasing the resulting ice from behind the boat. But there is a scientific consensus that perpetual motion is impossible. What is wrong with Elvis's idea?

a) Heat cannot transfer spontaneously between objects having the same temperature.

b) His idea violates the first law of thermodynamics (the law of conservation of energy).

c) His idea violates the second law of thermodynamics (the entropy of an isolated system never decreases).