The Aleutian Company produces two productsRings and Dings; they are manufactured in two departmentsFabrication and Assembly. Data for the products and departments are as follows. Rings: 1,000 units; 4 labor hours per unit; and 6 machine hours per unit. Dings: 2,000 units; 3 labor hours per unit; and 9 machine hours per unit. All of the machine hours take place in the Fabrication Department, which has an estimated total overhead of $90,000. All of the labor hours take place in the Assembly Department, which has an estimated total overhead of $105,000. The Aleutian Company uses departmental overhead rates. The Fabrication Department uses machine hours for an allocation base, and the Assembly Department uses labor hours. What is the Assembly Departments overhead rate per labor hour? a $10.50 b $19.50 c $3.75 d $4.38