When a Spectral-Type G2 Star Like the Sun Leaves the Main

Multiple Choice

When a spectral-type G2 star like the Sun leaves the main sequence:

A) its luminosity and surface temperature both stay the same
B) its luminosity and surface temperature both decrease
C) its luminosity increases and its surface temperature decreases
D) its luminosity and surface temperature both increase
E) its luminosity decreases and its surface temperature increases