Warren Has Earned Himself a Reputation for Being the Class

Warren has earned himself a reputation for being the class clown.His teacher, Ms.Dafoe, used to laugh at Warren's funny remarks, but is now trying to discourage Warren's disruptive behaviour by ignoring his jokes.In spite of Ms.Dafoe's attempts to ignore Warren, Warren sometimes tells a joke so funny that Ms.Dafoe laughs in spite of herself.Rather than decreasing his joke-telling, Warren begins telling even more outrageous jokes.Inadvertently, Ms.Dafoe is modifying Warren's joke-telling behaviour through:

A) punishment.
B) extinction.
C) shaping.
D) negative reinforcement.