Jessica loves to travel by air. She enjoys being in an airplane and experiencing the excitement of flying. However, Jessica's last three flights were highly turbulent and made her anxious and physically sick. Consequently, Jessica now fears flying. In this scenario, in the context of classical conditioning, Jessica's fear of flying is a(n) _____.
A. unconditioned stimulus
B. unconditioned response
C. conditioned stimulus
D. conditioned response
a) unconditioned stimulus
b) unconditioned response
c) conditioned stimulus
d) conditioned response