2) Select costs related to Apple's iPhone are listed below. Identify each cost as either direct materials, direct labor, manufacturing overhead, or selling and administrative expenses. Then, identify each cost as a product or period cost. DM, DL, OH or S&A Period or Product Cost Display screen Assembly-line supervisor salary Wages for assembly workers Salary of the chief executive officer Glue to hold iPhone cases together Uniforms provided for each factory worker Wages for retail store worker Depreciation on robotic equipment used in assembly