Chirp Chirp Industries makes custom deluxe birdhouses. Below is a list of some of the products that are used to construct these birdhouses. Determine if these costs are fixed or variable costs, and then determine if these costs are product costs or period costs. $$10,000$ per month $-$ rent for office building $$6,000$ per year $-$ depreciation for building equipment $$3,000$ per month $-$ Selling and Administrative Costs $$25$ per board foot $-$ wood to make the birdhouses $$65,000$ per year $-$ salary for shop supervisor Dependent on order $-$ glue, paint, and other materials to build the houses $$15$ per hour $-$ factory labor to build the houses