Answer:
The unconditioned response in the scenario is the following one:
"Though she never learned to respond this way, Jetta jumped in surprise because Willy's tap had startled her."
Explanation:
It is an unconditioned response, since Etta had neither been taught nor was used to responding to a tap on the back the way she did, that is, by jumping in surprise. She was not expecting her friend to approach her in such a way, so her response was a totally, say, instinctive thing. It was not like Willy approached Etta, said hi, then she stood up and shook his hand, as she had learned before and had also been conditioned to do ever since she was a child, as a civilized person.
