An example of conditioned reflex is
D. Salivation in Dog on seeing bread as found by Pavlov
Reason: Conditioned reflexes are acquired reflexes during the life time of an individual. They are absolutely an individual entity and are, therefore not constant, they may disappear and reappear again. Ivan Pavlov, a Russian physiologist discovered for the first time the existence of conditioned reflexes and therefore, he is called the father of conditioned reflexes. Pavlov had carries experiments with a dog. He rung bell every time just before the food was placed in the dog’s mouth. Gradually the dog learnt to associate the bell with food. The dog would salivate when the bell was rung even though no food was placed in its mouth. Finally Pavlov called food, unconditioned stimulus, salivation in response to food an unconditioned response, sound of the bell the conditioned stimulus and salivation in response to the conditioned response.