Black Company Uses the Weighted-Average Method in Its Process Costing

Black Company uses the weighted-average method in its process costing system. company's ending work in process inventory consists of 5,000 units, 80% complete with respect to materials and 50% complete with respect to labour and overhead. If the total dollar value of the inventory is $60,000 and the cost per equivalent unit for labour and overhead is $8.00, the cost per equivalent unit for materials must be?

A) $8.00.
B) $4.00.
C) $10.00.
D) $5.00.