Karen's Boyfriend Gets Very Excited Whenever He Smells Pizza as He

Karen's boyfriend gets very excited whenever he smells pizza as he walks by the pizza place where she works because whether Karen is working then or not,he still associates the place with Karen.Which of the following correctly identify the unconditioned stimulus and the conditioned stimulus?

A) unconditioned stimulus = Karen;conditioned stimulus = pizza place
B) unconditioned stimulus = pizza place;conditioned stimulus = Karen
C) unconditioned stimulus = the pizza smell;conditioned stimulus = Karen
D) unconditioned stimulus = Karen;conditioned stimulus = excitement