Pappy Corporation received cash of $13,500 on September 1, 2010 for one year's rent in advance and recorded the transaction with a credit to Unearned Rent. The December 31, 2010 adjusting entry is
a. debit Rent Revenue and credit Unearned Rent, $4,500.
b. debit Rent Revenue and credit Unearned Rent, $9,000.
c. debit Unearned Rent and credit Rent Revenue, $4,500.
d. debit Cash and credit Unearned Rent, $9,000.