Correct Option: A

The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons. Neutron stars are very hot and are supported against further collapse by quantum degeneracy pressure due to the Pauli’s exclusion principle. This principle states that no two neutrons (or any other fermionic particles) can occupy the same place and quantum state simultaneously. A typical neutron star has a mass between about 1.4 and 3.2 solar masses ( Chandrasekhar Limit), with a corresponding radius of about 12 km if the Akmal– Pandharipande–Ravenhall equation of state (APR EOS) is used.