Final answer:
Tracy's avoidance of household pets after being bitten by her neighbor's dog is an example of classical conditioning.
Step-by-step explanation:
The student's situation, where Tracy was bitten by her neighbor's dog and now avoids all household pets, is an example of classical conditioning. Classical conditioning occurs when an organism learns to associate a neutral stimulus (in this case, household pets) with an unconditioned stimulus (the pain from being bitten) and develops a conditioned response (fear or avoidance).