According to Melzack and Wall's "Gate Theory" of Pain, Why

Multiple Choice

 According to Melzack and Wall's "gate theory" of pain, why does rubbing your elbow after you bump it help reduce the pain?

A) Rubbing produces an increased release of endorphins.
B) Rubbing produces a refractory period in nociceptors, preventing their further activation.
C) Input from rubbing competes with ascending pain messages.
D) The act of rubbing has a placebo effect on the pain.