Those Interior Regions of a Protostar That Are Relatively Cool

Those interior regions of a protostar that are relatively cool are more likely to transport energy by:

A) conduction, because the atoms are close enough together to act as a solid.
B) convection, because the hydrogen tends to form the H^- ion, a good absorber of radiation.
C) radiation, because the atoms move too slowly at these temperatures for convection to be effective.
D) radiation, because low temperature atoms produce copious amounts of visible light.