Answer:
The innermost orbitals
Step-by-step explanation:
The Bohr's model of the atom was based on the quantum mechanics developed by Planck.
He suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus. Based on this concept that electrons move around in permissible orbits, the ground state orbital which is the innermost orbital and the closest to the nucleus is of the lowest energy. The excited state is any higher energy level than the ground state.