Problem: Every time Uncle Troublemaker visits, he plays a joke on Tommy. He gives Tommy a candy and as soon as Tommy is about to put the candy in his mouth, Uncle Troublemaker pops a balloon behind Tommy's ear, startling him. Uncle Troublemaker then laughs and says 'Got you again'. Soon, Tommy develops a fear for candies and refuses to eat it. Tommy is not even able to look at candies without bursting out into tears. Tommy's behaviour can be explained as: Question options: modeling imprinting operant conditioning classical conditioning