ABC Manufacturing Inc. ends the month with two jobs still in progress. Job 5 has $10,000 of materials, $2,000 of direct labor and $8,000 of manufacturing overhead allocated. Job 6 has $30,000 of materials, $2,000 of direct labor and $12,000 of manufacturing overhead allocated. The cost of goods sold for the month was $40,000 and there was no finished goods in stock as the month ended. If the manufacturing overhead was underallocated by $10,000, which of the following choices would be the correct way to prorate it based on ending balances before proration? a. Job 6 should be allocated another​ $6,000 of cost
b. Job 5 should be allocated another​ $6,000 of cost
c. Cost of goods sold should be reduced by​ $4,000
d. Cost of goods sold should be increased by​ $4,000