Answer:
Classical conditioning
Step-by-step explanation:
Classical conditioning: In psychology, the term classical conditioning is defined as a type of associative learning, and is discovered by the famous psychologist named Ivan Pavlov, while researching with dogs based on the dog's digestion process.
In psychology, classical conditioning is a process that involves a CS or conditioned stimulus that begins to be associated with an unconnected US or unconditioned stimulus to create a behavioral response which is known as CR or conditioned response ( formerly a neutral stimulus).
In the question above, the boy learned to become anxious in this situation through the process of classical conditioning.