In 2017, Costello Company performs work for a customer and bills the customer $10,000; it also pays expenses of $3,000. The customer pays Costello in 2018. If Costello uses the accrual-basis of accounting, then Costello will report:_____
a. revenue of $10,000 in 2018.
b. revenue of $10,000 in 2017.
c. net income of $7,000 in 2018.
d. expenses of $3,000 in 2018.