Active Education Sells Tickets in Advance for Their Weekly Productions

Active Education sells tickets in advance for their weekly productions and records the proceeds as Unearned revenue.At the end of each month,they make an adjusting entry to account for the tickets used during the month (Ticket revenue.) At March 1,the Unearned revenue account had a credit balance of $3,000.During March,they sold 300 tickets at $20 each,and 250 tickets were used during the month.What is the balance in Unearned revenue at the end of March?

A) Credit balance of $4,000
B) Debit balance of $4,000
C) Credit balance of $2,000
D) Debit balance of $2,000