Final answer:
True, planets with molten interiors have geological activity such as volcanism, driven by internal heat, while those with solid interiors do not.
Step-by-step explanation:
The statement that planets with molten interiors exhibit geological activity while those with solid interiors do not is true. Geological activity, including processes such as volcanism and mountain building, is fundamentally driven by the heat escaping from a planet's hot interior. In contrast, smaller bodies like our Moon have cooled down and ceased their geological activity. The larger a planet or moon, the longer it retains internal heat, which is responsible for geological activity. Exceptions like Jupiter's moon Io show unusual geological activity due to tidal heating from Jupiter's gravitational pull, offering a fascinating contrast to the relationship between size and geological activity.