Io has a smooth, nearly crater-free surface because:
A) it has not been bombarded by meteorites.
B) the gravitational effects on Io are slight.
C) it is not tectonically active.
D) of frequent lava flows.

Question

Quizplus · Accepted Answer

The most likely reason for Io's smooth surface is frequent lava flows. Io is one of the most volcanically active bodies in the solar system and has over 400 active volcanoes. These frequent lava flows would quickly cover up any impact craters, leading to a smooth surface.

Io Has a Smooth, Nearly Crater-Free Surface Because