Use the Graph Above Showing Data for the Brightest Galaxies

Use the graph above showing data for the brightest galaxies in clusters of galaxies to answer the following question. You find a cluster of galaxies, but you do not know how far away it is. The brightest galaxy's infrared color is 0.65. Given the data for brightest galaxies in the graph above, your best estimate for the distance is

A) 2) 5 × 109 (2.5 billion) light years.
B) 1 × 109 (1 billion) light years.
C) 4 × 109 (4 billion) light years.
D) It is impossible to say since there are exceptions.