A company purchased office supplies costing $3,000 and debited Supplies for the full amount. At the end of the accounting period, a physical count of office supplies revealed $900 still on hand. The appropriate adjusting journal entry to be made at the end of the period would be:

1. debit Supplies Expense, $2,100; credit Supplies, $2,100.
2. debit Supplies, $2,100; credit Supplies Expense, $2,100.
3. debit Supplies Expense, $3,900; credit Supplies, $3,900.
4. debit Supplies, $900; credit Supplies Expense, $900.