The Mass of the Solar Nebula That Began Contracting to Form

The mass of the solar nebula that began contracting to form the solar system was estimated to be

A) 1 solar mass, the same as the mass of the solar system today.
B) only a fraction of a solar mass because additional mass has since been attracted from nearby objects.
C) a few solar masses.
D) thousands of solar masses to allow for the mass energy radiated away since the formation.