The Dark Matter Halo Is Estimated to Extend Out About

Multiple Choice

The dark matter halo is estimated to extend out about 12 times farther from the galactic center than the solar system's position. How does this compare with the distance to the nearest large galaxy, Andromeda (M31) , which is 2.2 million light-years away?

A) The dark matter halo reaches only about 1 percent of the way to M31.
B) The dark matter halo reaches about one-seventh of the way to M31.
C) The dark matter halo just falls short of M31. If the Andromeda Galaxy has its own dark matter halo, the two must overlap.
D) Earth's dark matter halo engulfs M31.