RR Lyrae Variables Are Likely to Be Found In

Multiple Choice

RR Lyrae variables are likely to be found in:

A) very young clusters, where high-mass stars are undergoing core hydrogen burning.
B) giant molecular clouds, where protostars are forming from gas and dust clouds.
C) young-to-intermediate-age clusters, where high-mass stars are undergoing central helium burning.
D) globular clusters, where low-mass stars are undergoing core helium burning.