Harry Potter is a small street vendor service who contracts to produce and sell molded plastic souvenirs (key chains, commemorative plastic coins, plastic animals, etc.) at small, county carnivals. As owner of the firm, Harry must decide how much of each product to produce. A key element of this decision is 1. the fixed cost of production. 2. the cost of his selling booth. 3. the cost of bookkeeping services. 4. how costs will vary as he changes the level of production.