Astronomers Originally Rejected the Idea That White Dwarfs Could Rotate

Astronomers originally rejected the idea that white dwarfs could rotate fast enough to be responsible for pulsar radiation. However, they soon accepted the idea that neutron stars could produce pulsar radiation. Why this difference?

A) The earlier rejection was mistaken. With sufficient evidence astronomers have come to believe that both white dwarfs and neutron stars can produce pulsar radiation.
B) There are two types of white dwarfs: those that produce Type Ia supernova and those that do not. The earlier rejection applied to the second type. It is now believed that the Ia supernova type white dwarfs, along with neutron stars, can produce pulsar radiation.
C) Neutron stars are smaller and even more dense than white dwarfs. Thus, they can rotate at tremendous rates without flying apart.
D) Neutron stars are held together by nuclear forces that are much stronger than the gravitational forces operating in white dwarfs. Thus, the surface of a neutron star can pulse in and out much more quickly than the surface of a white dwarf.