What is the ultimate cause of the ability of male zebra finches to discriminate between the songs of established neighbours and those of strangers?

A) Neurons cease to respond to the sound of an established neighbour.
B) Zebra finches are capable of selective learning.
C) Zebra finches are genetically programmed to tolerate territory-holding neighbours but to repel invaders.
D) Male zebra finches produce more offspring by saving their energy for real battles.