Jan Never Used to Worry About Driving in the Snow

Jan never used to worry about driving in the snow until she skidded off the highway one morning during a heavy snowfall.As the back end of the car started to fishtail, Jan's heart started to race and she became terrified.Now she finds that just getting into her car when there is snow falling causes her to become extremely agitated.In this example of classical conditioning, the car sliding on the icy roadway is:

A) an unconditioned response
B) a conditioned stimulus
C) an unconditioned stimulus
D) a conditioned response