You Measure the Chemical Abundances and Space Motions of Stars

You measure the chemical abundances and space motions of stars near the Sun, and plot your data in the figure shown below. The stars separate into two distinct groups, which you label A and B. These groups are, respectively, in which two stellar components of the Milky Way?

A) disk and halo
B) bulge and disk
C) halo and disk
D) halo and bulge
E) globular clusters and halo