Manu Question 17 4 pts Using the information below, determine the nature of the below costs under variable costing: Indirect materials ($.20 a unit) is considered to be a Period Expense. considered to be a Period is v considered to be a Period Indirect Labor (salary) ($90,000 a year) Expense. Indirect Labor (hourly) ($15 an hour) Expense. is Maintenance supplies ($12 per unit) is not Expense. considered to be a Period