In a periodic system, if the accounting records show an opening inventory balance of $15800 and a physical count shows a balance of $20600, it is necessary to

b) debit Merchandise Inventory and credit Cost of Goods Sold for $4800.

d) both a) and c).

a) debit Income Summary and credit Merchandise Inventory for $15800.

c) debit Merchandise Inventory and credit Income Summary for $20600.