Some of the Invisible Matter in Our Galactic Halo Has

Multiple Choice

Some of the invisible matter in our Galactic halo has been shown to be white dwarfs by:

A) direct detection with optical telescopes, such as the Hubble Space Telescope.
B) direct detection with gamma-ray observations from the Fermi Telescope.
C) observations of Type I supernovae.
D) the gravitational microlensing technique.
E) watching white dwarfs in the Galactic halo pass in front of distant galaxies.