Supernova Remnants _____

Supernova remnants _____.

A) always contain pulsars, because pulsars supply the ionizing radiation
B) often last longer than a pulsar does, so the central pulsar may no longer be visible
C) rarely contain pulsars, because pulsar radiation disrupts the remnant
D) may not contain a pulsar, if the supernova explosion kicked the pulsar away at high speed
E) never contain pulsars