Astronomers Have Discovered Pulsars Spinning 500 X Per Second or More

Astronomers have discovered pulsars spinning 500 x per second or more. How do astronomers think pulsars got to be spinning so outrageously fast?

A) Because the neutron stars that are the pulsars were small when they were born, all pulsars should be spinning this fast or faster
B) Such fast-spinning pulsars have companion stars near them, which dump material on the pulsar and that spins it faster and faster
C) Pulsars are planets very close to their stars, and they have to spin so fast so they don't fall in
D) Such pulsars were thrown out of their original location because the supernova explosion that produced them was not the same energy in all directions; this being pushed to one side made them spin faster
E) Astronomers have no suggestion for why such fast-spinning pulsars exist
Section 23.6: They Mystery of the Gamma-ray Bursts