B. Internet Telephony would be my best guess. I'm not that good with computers. Hope this Helps :-)
Answer and Explanation:
For returning four columns from the Invoices table, named Number, Total, Credits, and Balance the SELECt statement is as follows
Select Invoice Number As Number
Invoice Total As Total
Payment total + credit total As Credits
Invoice total
(Payment total + credit total) As Balance
These are displayed as above
