Answer: D - Planetary Model
Explanation: This is a model proposed by a scientist named Niels Bohr. It is known as Bohr Atomic Model.
Niels Bohr in 1913 proposed a model of the atom to explain the stability of orbits around the nucleus.
The Bohr Atomic Model is a system that contains small dense nucleus surrounded by orbiting electrons. This is very close to the solar system but without gravity. Force of gravity being replaced by electrostatic forces.