The following information is available for Murray Manufacturing at year-end: Beginning raw materials inventory 6,000 Ending raw materials inventory $8,000 Materials purchased 13,000 Direct labour 4,000 Manufacturing overhead Applied 15,000 Beginning work in process inventory 8,000 Ending working in process inventory 5,000 What was the cost of goods manufactured during the period? Select one: a. $33,000 b. $28,000 c. $35,000 d. $16,000