The Following Transactions for the Month of March Have Been $\$ 9,000$

The following transactions for the month of March have been journalized and posted to the proper accounts. Mar. I Martinez invested $\$ 9,000$ cash in his new design services business.
Mar. 2 Paid the first month 5 rent of \$800.
Mar. 3 Purchased equipment by paying $3,000 cash and executing a note payable for $5,000.
Mar. 4 Purchased office supplies for $\$ 750$ cash.
Mar. 5 Eilled a client for $\$ 10,000$ of design services completed.
Mar. 6 Received $8,000 on account for the services previously recorded.
-According to the above transactions. What is the ending balance in the Service Revenue account?

A) $19,000
B) $9,000
C) $10,000
D) $8,000