Kirsten Is Trying to Train Her Dog,Sadie,to Come When She

Kirsten is trying to train her dog,Sadie,to come when she calls.She starts by calling her name,and when Sadie looks up,she gives her a treat.She does this a few times.Next,whenever Sadie stands up when her name is called,Kirsten gives her the treat.Finally,Sadie must come all the way over to Kirsten before she gets her treat.Kirsten is using ____________ to train Sadie.

A) classical conditioning
B) stimulus discrimination
C) shaping
D) negative reinforcement