After Pavlov Trained His Dogs to Respond to the Sound

Multiple Choice

After Pavlov trained his dogs to respond to the sound of a bell by salivating,he might have decided to show the dogs a striped handkerchief each time he rang the bell.Eventually,the handkerchief would have been able to cause the dogs to salivate,even if the bell was not sounded.This is an example of _________ conditioning.

A) graduated
B) tertiary
C) second-order
D) elevated