If Stars Rotate with Periods of Tens of Days, Why

Multiple Choice

If stars rotate with periods of tens of days, why does a neutron star rotate several to thousands of times a second?

A) When a neutron star collapses, the intensified magnetic field causes it to rotate much more quickly.
B) When a neutron star collapses, its rotation is kicked up by the ejected material from the supernova.
C) When a neutron star collapses, its rotation rate speeds up because of conservation of angular momentum.
D) The collapsing neutron star becomes hot and the fast rotation is the result of thermal energy.