Final answer:
To insert a new row above the selected row in spreadsheet applications, you should use the shortcut key Ctrl + +.
Step-by-step explanation:
To insert a new row above the selected row in many spreadsheet applications such as Microsoft Excel, the correct shortcut key to use is Ctrl + +. After selecting the row, pressing Ctrl and the + (plus) key at the same time will prompt the application to insert a new row directly above the one that is currently selected. This is a useful keyboard shortcut for quickly managing and organizing data within a spreadsheet.