What can result from a massive star undergoing a Type II supernova?

A massive star undergoing a Type II supernova results in a neutron star or a black hole due to the core collapse that occurs at the end of the star's life cycle. When a massive star exhausts its nuclear fuel, it can no longer support itself against gravitational collapse. The core collapses under its own gravity, leading to extremely high densities. If the remaining core after the supernova explosion is between about 1.4 and 3 solar masses, it will become a neutron star, where the immense gravitational forces compress it to the point where electrons and protons combine to form neutrons. If the remaining core exceeds approximately 3 solar masses, the gravitational pull is so strong that it continues to collapse, forming a black hole, from which nothing can escape.

In contrast, other options like a planetary nebula and a white dwarf are associated with less massive stars that evolve differently. A red giant is a phase in a star's life cycle prior to supernova that does not pertain to the outcome of a Type II supernova. This distinction highlights the specific processes and final states that result from the death of different types of stars.