Roman is the chief executive officer of salty snax corporation. roman’s responsibilities include decisions on product development, marketing, and other significant business directions. roman is subject to the approval and oversight of salty snax’s board of directors. teri is a salty snax manager whose duties include the firm’s day-to-day hiring, firing, purchasing, and selling. umberto is a salty snax salesperson, whose daily activities are controlled by teri. velma writes sales manuals and promotional materials for salty snax’s products according to roman’s instructions and subject to salty snax’s control, but has no dealings with the company’s customers or suppliers. warren writes copy on a contract-per-project basis and is not otherwise subject to salty snax’s control. who is a principal? who is an agent? who is an employee? who is an independent contractor?