Final answer:
Companies who send salespeople to customers' homes or places of work are making use of D) Direct selling.
Step-by-step explanation:
Companies who send salespeople to customers' homes or places of work are making use of D) Direct selling.
Direct selling is a method used by companies to sell products or services directly to consumers, without using a retail store or middleman.
Examples include Avon, Tupperware, and Amway. By sending salespeople directly to customers' homes or workplaces, companies can provide personalized demonstrations and build strong relationships with their customers.