Henna Hair Salon purchased supplies for $6,000 and debited Supplies for the full amount. At the end of the accounting period, $1,800 worth of supplies were still on hand. Identify the adjusting entry needed at the end of the period. debit Supplies $4,200; credit Supplies Expense $4,200 debit Supplies Expense $7,800; credit Supplies $7,800 debit Supplies $1,800; credit Supplies Expense $1,800 debit Supplies Expense $4,200; credit Supplies $4,200