How can I solve this problem? I tried, but i keep getting different numbers?Thank you

Jared Beverage Corporation uses a process costing system to collect costs related to the production of its celery flavored cola. The cola is first processed in a Mixing Department and is then transferred out and finished up in the Bottling Department. The finished cases of cola are then transferred to Finished Goods Inventory. The following information relates to the company's two departments for the month of January: Mixing Bottling Cases of cola in work in process, January 1 10,000 5,000 Cases of cola completed/transferred out during January 65,000 Cases of cola in work in process, January 31 4,000 7,000 How many cases of cola were completed and transferred to Finished Goods Inventory during January? Select one: O a. 70,000 O b. 63,000 O c. 58,000 O d. 77,000