The following transactions have been journalized and posted to the proper accounts. March is the first month of business operations Mar. 1 The business received $10,000 cash and issued common stock to stockholders. Mar 2 Paid the first month's rent of $500 Mar 3 Purchased equipment by paying $3.000 cash and executing a note payable for $6,000 Mar 4 Purchased office supplies for 5550 cash Mar. 5 Billed a client for $13,000 of design services completed Mar. 6 Received $8,000 on account for the services previously recorded What is the ending balance in the Service Revenue account? O A. $13,000 OB. $8,000 OC. $18,000 OD. $10,000