Answer:
the Work in Process Inventory account
Explanation:
The journal entry to record the manufacturing overhead costs applied to the cost of production includes -
Debit   Work in Process Inventory account   XXXX
Credit  Manufacturing overhead            XXXX
As the work is in progress, it cannot be a finished goods inventory or even a cost of goods sold account. Again, raw materials inventory will not come here as manufacturing overhead costs assigned to the cost of production. Therefore, option C is correct.