3) Classify each of the following costs as either a product cost or a period cost: (15 points) a) Depreciation on equipment i) Oil to lubricate machines b) Advertising Expense j) Salary of the CEO c) Sales Commission k) Salaries of sales staff d) Salaries of factory workers l) Fabric used to make clothes e) Property taxes for factory m) Insurance for factory building f) Repair costs of factory machines n) Salaries of administration g) Research and development costs o) Utility cost for factory h) Depreciation of headquarter building