Indicate whether a debit or credit is required to close each of the following accounts. Use the symbols D if a debit is required, C if a credit is required, and N if the account is not closed at the end of the period.
a. Salary Expense
b. Unexpired Insurance
c. Consulting Fees Earned
d. Depreciation Expense
e. Dividends
f. Retained Earnings
g. Interest Revenue
h. Accumulated Depreciation
i. Income Taxes Expense
j. Unearned Revenue
k. Income Summary (of a profitable company)
l. Income Summary (of an unprofitable company)