In 2011 Costello Company performs work for a customer and bills the customer $10,000; it also pays expense of $3,000. The customer pays Costello in 2012. If Costello uses the accrual basis of accounting, then Costello will report:
A. revenue of $10,000 in 2011
B. revenue of $10,000 in 2012
C. expenses of $3,000 in 2012
D. net income of $7,000 in 2012