Wages for employees who work directly in production is what type of cost? O direct labor selling and administrative expense o direct materials O factory overhead Hourly wages of operators of robotic machinery used in production is what type of cost? O direct materials factory overhead O selling and administrative expense O direct labor Depreciation of copying machines used in the Marketing Department is what type of cost? direct labor O selling and administrative expense factory overhead O direct materials Cost of advertising in a national magazine is what type of cost? O selling and administrative expense O factory overhead O direct materials direct labor