Why Can't Dark Matter Halos Collapse to Be the Same

Multiple Choice

Why can't dark matter halos collapse to be the same size as the visible parts of galaxies?

A) Dark matter can't dissipate its energy through collisions.
B) Dark matter is mostly made of mini-black holes.
C) Dark matter has much more angular momentum.
D) Dark matter annihilates when it begins to get that dense.
E) Dark matter particles are too large to collapse that much.