Planets and moons showing the most craters have b. molten cores. c. the oldest surfaces. d. been hit by meteors the most times.

Answer: c. the oldest surfaces.

Explanation: Craters form on the surfaces of moons and planets due to collision with impacting bodies such as comets. When this happens the debris scatter in different directions, boring large holes on the surface of the moon or planet. Older bodies in the solar system were exposed to comets and meteoroids which were more common in the early formative years of our solar system so older moons and planets have more craters.

Scientists use the characteristics of a crater to estimate how old a moon or planet is. The size, number and the state of erosion of the crater can be used to determine the age of a planet.