Jerome Is Training to Be a Vacuum Cleaner Sales Person

Multiple Choice

Jerome is training to be a vacuum cleaner sales person. Initially, he got paid for each customer he called on, even if the customer did not ask for a demonstration. Currently, he only gets paid for actually demonstrating the product. Eventually, he will only get paid for actually closing a sale. In this example, Jerome's sales skills are being developed through the use of

A) classical conditioning.
B) modeling.
C) negative reinforcement.
D) shaping.