What statement represents the second law of thermodynamics?

Correct Answer: Option C — When heat is transferred from one body to another, the direction of heat flow is unidirectional from the relatively hot body to the relatively cold body.

The Second Law of Thermodynamics establishes the direction of heat flow. It dictates that thermal energy will spontaneously move only from a body of higher temperature to a body of lower temperature. Heat cannot move from a cold body to a hot body without the input of external work.