Carrie Fed Her Cat Canned Tuna That Was Opened with an Electric

Multiple Choice

Carrie fed her cat canned tuna that was opened with an electric can opener. Even when she was merely opening a can of corn, her cat responded physically as if it were about to be fed. In this example, the conditioned stimulus is the

A) sound of the electric can opener.
B) eating behaviours.
C) corn.
D) tuna.