DrCabbot Is Recording from a Mirror Neuron in a Monkey's

Dr.Cabbot is recording from a mirror neuron in a monkey's brain.When will the neuron fire?

A) only when the monkey is performing a specific action,but not when it sees someone else perform the same action
B) only when the monkey is watching someone else perform a specific action,but not when it performs the same action
C) only when the monkey is watching itself perform an action in front of a mirror
D) when the monkey is performing a specific action,and also when it watches someone else perform the same action