PPW Co. leased a portion of its store to another company for eight months beginning on October 1, at a monthly rate of 6,400 cash on October 1, which PPW Co. recorded as unearned revenue. The journal entry made by PPW Co. at year-end on December 31 would include: 
A、A debit to Rent Earned for 2,400.
C、 A debit to Cash for 2,400.
E、 A debit to Unearned Rent for $4,000.