Which planets are referred to as part of the inner solar system?

The inner solar system consists of the four terrestrial planets: Mercury, Venus, Earth, and Mars. These planets are characterized by their rocky compositions and are found closer to the Sun compared to the outer planets. They have solid surfaces and are relatively smaller in size and mass compared to their outer counterparts.

In contrast, the options that include outer planets or other celestial bodies do not belong to the classification of the inner solar system. For instance, Jupiter, Saturn, Uranus, and Neptune are gas giants located in the outer solar system, while the asteroids and comets are not classified as planets at all. Pluto, once considered the ninth planet, is now classified as a dwarf planet and is also part of the outer solar system. Therefore, the correct identification of the inner solar system is exclusively the four rocky planets listed.