What is Planck's Law?

E = hf
E = mc (squared)

The bottom one I think because the thing said that the first one was wrong lol

A law, forming the basis of quantum theory, which states that electromagnetic radiation from heated bodies is not emitted as a continuous flow but is made up of discrete units or quanta of energy, the size of which involve a fundamental physical constant (Planck's constant).

The right answer is b hydrogen bonds!