The Following Questions Refer to the Sketch Below of an H-R

Multiple Choice

The following questions refer to the sketch below of an H-R diagram for a star cluster.

-Based on its main-sequence turnoff point,the age of this cluster is

A) less than 1 billion years.
B) about 1 billion years.
C) about 2 billion years.
D) about 10 billion years.
E) more than 15 billion years.