Why are galaxies much denser and compact than their dark matter halos? (Select all that apply)

A. Galaxies contain more stars than dark matter

B. Dark matter halos are more diffuse than galaxies
C. Dark matter halos are more massive than galaxies
D. Galaxies contain more gas than dark matter

A. Galaxies contain more stars than dark matter
B. Dark matter halos are more diffuse than galaxies
D. Galaxies contain more gas than dark matter