The outer planets are ________  the inner planets.

The correct answer is: Larger than

The correct option is b)Larger than.
Because the inner planets were much smaller than the outer planets, they had relatively low gravity and could not draw large amounts of gas into their atmospheres. In the outer regions of the solar system, where temperatures are cooler, other elements such as water and methane did not evaporate, allowing giant planets to form. These planets are more massive than the inner planets, can attract large amounts of hydrogen and helium, and are composed primarily of hydrogen and helium, the most abundant elements in the solar system and the universe.