On January 1, Mountbatten Corporation paid $18,000 for a year's advance rent on a building and recorded it as Rent Expense. The rental period begins on January 1. When financial statements are prepared on March 31, the adjusting entry should include . (Do not round intermediary calculations. Only round your final answer to the nearest dollar.)

a. a credit to cash for $13,500
b. a crdit to rent expense for $13,500
c. a credit to prepaid rent for $4,500
d. a debit to rent expense for $4,500