Sky Corp.'s relevant range of activity is 6,000 - 10,000 units. When it produces 9,000 units its average costs per unit are: Direct materials $5.00 Direct labor $4.00 Fixed manufacturing overhead $3.00 $8.00 Variable manufacturing overhead If 6,000 units are produced, total manufacturing costs will be: $ 66,000 O A. $102,000 OB. $120,000 C. $129,000