ALT+F4 is the key which you can use to shut down system or application
B
Correct answer
Explanation
ALT+F4 is a keyboard shortcut primarily used to close the active application window in Windows operating systems. It does not directly shut down the computer system - for that, you would typically need to go through the Start menu or use a different shutdown procedure. The statement is imprecise because ALT+F4 closes applications, not the system itself.