Callisto, the Outer Galilean Satellite of Jupiter, Has a Surface

Callisto, the outer Galilean satellite of Jupiter, has a surface consisting of:

A) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves.
B) an ancient, icy crust covered with numerous craters and no surface cracks or groove belts that would indicate internal activity.
C) rock, heavily cratered like the highlands of our Moon.
D) a relatively young, icy crust covered with a network of streaks and cracks, and only a few impact craters.