Maryann and Don want to open their own deli. To do so, Maryann must give up her job, where she earns $20,000 per year, and Don must give up his part-time job, where he earns $10,000 per year. They must liquidate their money market fund, which earns $1,000 in interest annually. The rent on the building is $10,000 per year, and the expenses of necessities such as utilities, corned beef, and pickles are $35,000 annually. _____ is the explicit cost per year of operating the deli.