Which electrons have the most energy in an atom?

electrons in the innermost electron shell

electrons in the outermost electron shell

electrons in the nucleus

electrons in an electron cloud

The option B is correct.

The electrons in the outermost shell have higher energy.

Electrons in outer shells have higher average energy and travel farther from the nucleus than those in inner shells. This makes them more important in determining how the atom reacts chemically and behaves as a conductor, because the pull of the atom's nucleus upon them is weaker and more easily broken.