It Is Proposed That the Ordinary Matter and the Dark

It is proposed that the ordinary matter and the dark matter in the galaxy cluster 1E0657-56 have become separated. This is based on the assumption that:

A) the amounts of ordinary and dark matter are equal.
B) dark matter responds only to gravitational forces.
C) the gravitational force for dark matter decreases with distance like 1/r.
D) dark matter is repelled from ordinary matter.