Final answer:
The correct example of an unconditioned response is B) Blinking in response to a puff of air. This is a natural reflex not learned through conditioning, unlike salivating at the sound of a bell, which is a conditioned response from Pavlov's experiments.
Step-by-step explanation:
The best example of an unconditioned response is B) Blinking in response to a puff of air. An unconditioned response is a natural, unlearned reaction to a stimulus. In this case, blinking is an automatic, reflexive response to the air puff, which is an unconditioned stimulus.
In contrast, salivating at the sound of a bell (A) is an example of a conditioned response, which is learned through classical conditioning. In Ivan Pavlov's well-known experiments, he paired the sound of a bell (conditioned stimulus) with the presentation of food (unconditioned stimulus), and after repeated pairings, the dogs learned to salivate (conditioned response) at the bell's sound, anticipating food.
Option C) Pressing a lever for a reward and D) Avoiding a specific food can be conditioned behaviors developed through either classical conditioning or another form of learning called operant conditioning. These behaviors are not automatic reflexes but are learned responses to certain stimuli.