If You Found a Star Cluster That Was 13 Billion

If you found a star cluster that was 13 billion years old and whose stars had fractions of heavy elements that were 100 times less than that in the Sun, what type of star cluster would this be and where would it most likely be located?

A) an open cluster that is likely to be in the disk
B) an open cluster that is likely to be in the stellar halo
C) a globular cluster that is likely to be in the thin disk
D) a globular cluster that is likely to be in the stellar halo
E) a globular cluster that is likely to be in the central bar