A quark-nova is the explosion driven by phase transition of the core of a neutron star to the quark matter phase (i.e., neutron star core collapse) leading to the formation of a quark star. The gravitational potential energy released (plus latent heat of phase transition) during this event is converted partly into internal energy and partly into outward propagating shock waves, which impart kinetic energy to the material that forms the ejecta (i.e., the outermost layers of the neutron star crust). The ejection of the outer layers of the neutron star is driven by the thermal fireball generated as the star cools from its birth temperature down to ~7.7 MeV. The fireball expands without losing or gaining heat, while pushing the overlaying crust and cooling fairly rapidly. The energy needed to eject the crust is less than 1% of the fireball energy, which is thought to be one of the most powerful explosions in the universe.

According to the passage, which of the following occurs during a quark-nova?

A. The crust of a neutron star is driven into the core of the star.
B. The ejecta are expelled by the shock waves generated by the fireball.
C. The fireball produced by a quark-nova contains 99% of its energy.