Answer:
D. The scientist uses tennis balls to show the position of the planets and Sun.
Explanation:
In a layman's terms, the solar system is a system consisting of the sun and the planets that orbits around it. These planets are as follows; Mercury, Mars, Earth, Saturn, Venus, Jupiter, Neptune, Uranus etc.
According to this question, using a physical model to represent or describe the solar system means the use of physical objects that can easily be seen or identified. Based on this explanation, the use of tennis balls to show the position of the planets and Sun suits the physical model description of our solar system.
