What Is the Approximate Age of the Star Cluster in the HR

What is the approximate age of the star cluster in the HR diagram below? (Hint: Main Sequence Stars of spectral between types A and B core supply of hydrogen is sufficient to last about 250 million years. Between A and F about 2 billion years. Type G about 10 billion years. Between K and M about 30 billion years..)

A) 200 million years
B) 2 billion years
C) 10 billion years
D) 30 billion years
E) The age of the cluster can not be estimated from an HR diagram of the cluster.