Stars Within a Cluster That Are at the Turnoff Point

Stars within a cluster that are at the turnoff point

A) have life expectancies that are equal to the age of the cluster.
B) are stars that are just becoming white dwarfs.
C) are stars that are just entering the main sequence portion of their evolution.
D) are stars that are about to supernova.
E) are stars that are generally spectral type G stars.