At the beginning of the current year, the Grant Company's work in process inventory account had a balance of $30,000. During the year, $68,000 of direct materials were used in production, and $66,000 of direct labor costs were incurred. Factory overhead for the year amounted to $90,000. Cost of goods manufactured is $230,000. The balance in work in process inventory on December 31 is Oa. $44,000 Ob. $24,000 Oc. $36,000 Od. $66,000