Brown and Jenkins (1968) trained pigeons to approach and eat grain whenever a food hopper was presented. After the birds were magazine-trained, they turned on a key light before the grain was delivered. The birds started to orient and move towards the lighted disk. Eventually, the pigeons began to strike the key. This is called:
(A) shaping
(B) response induction
(C) autoshaping
(D) auto-sign-tracking