Answer:
Positive reinforcement
Step-by-step explanation:
This is called classic conditioning first described by Pavlov. In his experiment a bell would ring a bell: stimuli then feed the dog and after a few incidences of this the dog would salivate in anticipation for food: reward. In this case the sound of the can opener would be the stumuli and the cat food is the reward which is the positive reinforcement since they behave in a desired way. i.e coming when called/hearing sound of can opener.