$1$

Java Joe operates a chain of coffee shops. The company pays rent of $$20,000$ per year for each shop. Supplies $($napkins$,$ bags, and condiments$)$ are purchased as needed. The manager of each shop is paid a salary of $$3,000$ per month, and all other employees are paid on an hourly basis. Relative to the number of customers for a shop, the cost of supplies is which kind of cost$?$