If a Protostar Were Able to Contract (Get Smaller) Without

If a protostar were able to contract (get smaller) without any change in its surface temperature, what would happen to its luminosity?

A) It is not possible to predict the change in the protostar's luminosity since other factors are involved.
B) The star's luminosity would increase due to the compression of the gas.
C) The star's luminosity would decrease due to the reduced surface area of the protostar.
D) The star's luminosity would remain the same since the temperature does not change.