In His Original Experiments, Pavlov Paired a Bell Tone with the Presentation

Multiple Choice

In his original experiments, Pavlov paired a bell tone with the presentation of food. After a while, the bell tone alone could provoke salivation. By the time this happened, the ____.

A) bell had become a conditioned stimulus
B) food had become a conditioned stimulus
C) animal had lost interest in the food
D) salivation had become an unconditioned response