Carl Wasn't Always Afraid of Stoplights, but When He Was

Multiple Choice

Carl wasn't always afraid of stoplights, but when he was little he was was kidnapped out of his mother's car while they were stopped at a stoplight. He was recovered within 48 hours. But now, even as an adult, he finds himself avoiding stoplights, and if he can't avoid them, he feels tension mounting. In classical conditioning paradigms, Carl's fear of stoplights is a(n)

A) unconditioned stimulus.
B) unconditioned response.
C) conditioned stimulus.
D) conditioned response.