Which statement is an example of the speaker's use of deductive logic?

A) If you are a plumber, then you probably are a person worth knowing.
B) If your dog has had fleas several times, then he needs to be bathed more often.
C) Just because you aren't valedictorian of the school doesn't mean you aren't smart.
D) If you are valedictorian of the school then you are the smartest person in the class.