The following information was obtained from the books of the Greybo Company for the year. Opening balances: Raw materials inventory $25,000 WIP inventory $55,000 Finished goods $5,000 Closing balances: Raw materials inventory $18,000 WIP inventory $105,000 Finished goods $15,000 The company purchased raw material inventory to the value of $90,000. Conversion costs of $85,000 were incurred during the year. The cost of goods sold during the year was: Select one: a. $122,000 b. $80,000 c. $32,000 d. $37,000 e. None of the above