The Most Important Reason Why Globular Clusters Are Useful for Finding

The most important reason why globular clusters are useful for finding the speed of the Sun in its orbit around the galaxy is that globular clusters:

A) on average rotate at the same speed as the Sun around the center of the galaxy.
B) are bright and easily seen at large distances.
C) are distributed uniformly around the galaxy.
D) on average do not rotate like stars in the disk of the galaxy.