Java joe's operates a chain of coffee shops. the company pays rent of $12,000 per year for each shop. supplies (napkins, bags, and condiments) are purchased as needed. the manager of each shop is paid a salary of $2000 per month, and all other employees are paid on an hourly basis. relative to the number of customers for a shop, the cost of rent is which kind of cost.-fixed cost-variable cost-mixed cost-relevant cost