Question

emission of light from an atom occurs when an electron
falls into the nucleus.
jumps from a lower to a higher energy level.
moves within its atomic orbital.
drops from a higher to a lower energy level.

Explanation:

When an electron drops from a higher - energy level to a lower - energy level, it emits a photon (light). Electrons do not fall into the nucleus (that would be a nuclear reaction, not light emission). When an electron jumps from a lower to a higher energy level, it absorbs energy. Moving within an atomic orbital (without a change in energy level) does not result in light emission.

Answer:

drops from a higher to a lower energy level.