When the Stars of the Following Open Clusters Are Plotted $\chi$

Multiple Choice

When the stars of the following open clusters are plotted on an H-R diagram, the luminosity values for the turning points are approximately (in solar luminosities) : Coma (7) , h + $\chi$ (600) , M67 (2) , and Pleiades (70) . Which cluster is youngest?

A) Coma
B) h + $\chi$
C) M67
D) Pleiades