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

Multiple Choice

Callisto, the outer Galilean moon 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) rock, heavily cratered like the highlands of Earth's Moon.
C) a relatively young, icy crust covered with a network of streaks and cracks and only a few impact craters.
D) a very dark and ancient icy crust covered with numerous craters, with no surface cracks or groove belts that would indicate internal activity.