When the Core of a Star Becomes Too Massive to Be

When the core of a star becomes too massive to be held up by the pressure associated with electron degeneracy, it

A) is unable to collapse further because of the rules of quantum mechanics.
B) collapses further until it is held up by the pressure of neutron degeneracy.
C) collapses further until it is held up by quark degeneracy.
D) cannot be prevented from further collapse and thus forms a black hole.