You walk past pizza hut and salivate in response to the aroma of freshly baked pizzas. what is this the result of?

This is a result of classical conditioning in humans. Classical conditioning pairs two stimuli in eliciting a response; one stimulus is a normal stimulus (unconditioned stimulus) and another is a learned stimulus (conditioned stimulus). 

In this case, humans normally salivate in response to eating; perhaps pizza from Pizza Hut from example. Food aromas and restaurant symbols do not normally elicit the response alone; but since the restaurant symbol and food aroma is paired with eating a pizza (which normally elicits the response), then the human will elicit the response in just seeing the logo of Pizza Hut and the smell of pizzas, without actually eating.

Is there any answer choices?