-What Is the Approximate Age of the Star Cluster in the H-R

Multiple Choice

-What is the approximate age of the star cluster in the H-R diagram?
(Hint: Main sequence stars of spectral types O and B have a core supply of hydrogen that is sufficient to last about 250 million years;types A and F,about 2 billion years;type G about 10 billion years;types K and M about 30 billion years.The apparent magnitude scale means that larger numbers are toward the bottom of the vertical axis.)

A) 200 million years
B) 2 billion years
C) 10 billion years
D) 30 billion years