What Causes the Radio Pulses of a Pulsar

Multiple Choice

What causes the radio pulses of a pulsar?

A) The vibration of the neutron star.
B) As the neutron star spins, beams of radio radiation sweep through space. If one of the beams crosses the Earth, we observe a pulse.
C) The neutron star undergoes periodic explosions of nuclear fusion that generate radio pulses.
D) The neutron star's orbiting companion periodically eclipses the radio waves that the neutron star emits.
E) A black hole near the neutron star absorbs energy and re-emits it as radio waves.