Answer:
c) Unearned Revenue $ 500, Revenue $ 500
Explanation:
When the cash was received on August 01, no accounting services were provided so the entry would have been:
Cash Debit $ 1,200
Unearned revenue Credit $ 1,200
Unearned Revenue is a liability account
On December 31, a recognition needs to be made for the services revenue earned and hence the amount for 5 months amounting is debited to unearned revenue and revenue credited with $ 500.