During the current period, a subsidiary entity sold inventories to its parent entity at a profit of $9 000. The goods had originally cost the subsidiary $21 000. At the end of the year all the inventories were still on hand. The adjustment entry to deal with this transaction on consolidation would include the following line item:

a- Cr Cost of sales $12 000.

b- Cr Cost of sales $30 000.

c- Cr Cost of sales $21 000.

d- Cr Cost of sales $9 000.