From Stage 4 to Stage 7 of Star Formation, the Object

From stage 4 to stage 7 of star formation, the object plotted on the H-R diagram moves sothat:

A) its luminosity decreases, while its temperature increases.
B) its luminosity decreases, while its temperature stays the same.
C) its luminosity increases, while its temperature increases.
D) its luminosity increases, while its temperature stays the same.
E) its luminosity stays the same, and its temperature stays the same.