Through research and development, a cable company has found a way to use its existing network lines to serve customers with a new product offering – home security systems. the company is offering the service for a lower monthly fee than most security companies. however, the sales force didn't see a lot of interest among its customers who had an existing security system from a competitor until they ran a promotion for reduced prices on equipment and free installation. which of the competitive forces is at play? a. cost conditions b. bargaining power of suppliers c. customer switching costs d. complementors