What do you notice about the distance between the terrestrial planets compared with the spacing between the gas giants

The spacing between the terrestrial planets is less than that between the gas planets.

Explanation:

Since the terrestrial planets which are Mercury, Venus, Earth and Mars have a distance of 0.4 AU, 0.7 A.U, 1.0 AU and 1.5 A.U respectively from while the gas planets which are Jupiter, Saturn, Uranus and Neptune have a distance of 5.2 AU, 9.6 AU, 19.6 AU and 30 AU respectively from the sun, we can see that the spacing between the terrestrial planets is much smaller than the spacing between the gas planets.

For example, the spacing between Mercury and Venus is 0.7 AU - 0.4 AU = 0.3 AU while that between Earth and Venus is 1.0 AU - 0.7 AU = 0.3 AU.

Also, the spacing between Earth and Mars is 1.5 AU - 1.0 AU = 0.5 AU.

Also too, the spacing between the gas planets is shown below  the spacing between Jupiter and Saturn is 9.6 AU - 5.2 AU = 4.4 AU while that between Uranus and Saturn is 19.6 AU - 9.6 AU = 10.0 AU.

Also, the spacing between Neptune and Uranus is 30 AU - 19.6 AU = 10.4 AU.

Thus, we can see that the spacing between the terrestrial planets is less than that between the gas planets.

Note that AU means astronomical unit and 1 AU is the distance between the Earth and the Sun. 1 AU = 1.50 × 10⁸ km

c) should be the answer.