Managerial Accounting: Please explain and solve with showing all steps.

34. The Assembly Department started the month with 35,000 units in its beginning work in process inventory. An additional 472,0000 units were transferred in from the prior department during the month to begin processing in the Assembly Department. There were 34,000 units in the ending work in process inventory of the Assembly Department. How many units were transferred to the next processing department during the month? a. 507,000 b. 473,000 c. 471,000 d. 541,000