Respuesta :
Answer:
The correct option is: D) Subatomic Particle
Explanation:
Electrons are the negatively charged, stable sub-atomic particles that exist in discrete energy levels, called the electron shells, around the nucleus of an atom.
Each electronic shell consists of a fixed number of electrons and these electronic shells are denoted by the symbol K, L, M, N, and so on.
Therefore, electron is the sub-atomic particle that exists at a discrete energy level.