Answer:
Unconditioned response (UCR)
Explanation:
Unconditioned response (UCR) is used in classical conditioning. It is an unlearned response. It is not conditioned. It occurs naturally.
For example, the food of the smell is unconditioned response and to feel hunger with the smell of food is the unconditioned response. Russian psychologist Ivan Pavlov was a person who has been proposed this concept.
Thus here in the above context if a person touches something hot, then reflex action will occur. This reflex action is an unconditioned response.
UCR = Reflexively withdrawing the hands from hot.