The image above was taken by the Galileo spacecraft as it visited the asteroid belt on its way to Jupiter. Shown in the image are two rocky-iron bodies. The large object on the left is an asteroid named Ida. The object on the right, which measures only about 1 mile across, is named Dactyl. Dactyl is a tiny moon that orbits the asteroid Ida. Dactyl orbits Ida due to
A.
the mutual gravitational attraction between the two objects.

B.
small differences in the objects' rocky-iron compositions.

C.
electrical energy transferred between the two objects.

D.
the magnetic force field that defines the asteroid belt.