Final answer:
Supplies expense is debited and supplies is credited for the amount of supplies used during the period that were originally recorded as an asset when purchased.
Step-by-step explanation:
The correct answer is a) debited, credited. When supplies are used during the period, the expense is debited and the supplies account is credited. This means that the supplies expense is recorded as an increase in expenses on the income statement, while the supplies account is reduced on the balance sheet.