Because of an alarming drop in the earnings of Microminds Ltd., Roger, the principal contract negotiator and president of the software development company, called a meeting to discuss productivity and customer satisfaction. At the meeting were Michael, troubleshooter, who helped customers over the phone who needed guidance in using the company's software; Ralph, receptionist and purchaser of the office supplies for the company; Keith and Jason, salesmen, hired on a commission basis, i.e., not as employees but as independent contractors; Mr. Toman, purchasing agent for the Vancouver School Board, an important customer; and Mr. Rice, purchasing agent for Matol Toys Ltd., also a customer. Which of these is an agent?