The correct answer for the given question is 4
Explanation:
In the given code it select the vendorName, invoiceNumber, invoiceDate, invoiceTotal from vendors ,invoices table. when required condition is fullfill i.e vendors .vendorID = invoices.vendorID and invoiceTotal >= 500 .
So their are 4 column in the result set i.e vendorName, invoiceNumber, invoiceDate, invoiceTotal .