What are the characteristics of terrestrial planets?

The characteristics of terrestrial planets are defined primarily by their solid, rocky surfaces. These planets, which include Mercury, Venus, Earth, and Mars, are located closer to the Sun compared to the gas giants. As a result of their composition and proximity to the Sun, they tend to have higher densities and are composed mainly of silicate rocks and metals.

Additionally, terrestrial planets generally have fewer moons than gas giants, and some, like Mercury and Venus, do not have any moons at all. The lack of multiple moons and the presence of a solid surface are key distinguishing features that categorize these planets separately from the large, gaseous planets that dominate the outer solar system.

This understanding aligns with the identified characteristics in the correct option and establishes it as the appropriate description of terrestrial planets.