Answer:
D. debit Unearned Rent Revenue, $4720; credit Rent Revenue, $4720.
Step-by-step explanation:
When the Cash was received for 6 month`s Rent the entry was :
Debit : Cash $28320
Credit : Unearned Rent Revenue $28320
At 31 July when 1 month`s rent expires the entry will be :
Debit : Unearned Rent Revenue (1/6 x $28,320) $4,720
Credit : Rent Revenue $4,720
thus
We reverse the liability - Unearned Rent Revenue and recognize Revenue for the month expired.