Final answer:
To exit a shell, the correct command is 'exit'. The 'exit' command closes the current shell window or terminal session, while other options like 'close', 'shutdown', and 'terminate' are not used for this specific function.
Step-by-step explanation:
Exiting the ShellTo exit a shell when it is no longer needed, the command that should be used is A) exit.In the context of an operating system, a shell is a command-line interface that allows users to interact with the computer's operating system through commands. When you are done working in a shell session, the proper command to terminate the session is 'exit'. This command will close the current shell window or terminal session, effectively logging you out if you are remotely accessing a system or ending your current session in a terminal window. While 'close', 'shutdown', and 'terminate' might be related terms used in computing, they do not perform the function of exiting a shell.The command that can be given to exit the shell is exit.
Explanation: When you are using a shell, such as the command line interface in a computer operating system, you can use the exit command to close the shell and return to the previous environment. This command is used to terminate the shell process. For example, in a UNIX-like system, if you are using the Bash shell, typing exit and pressing enter will close the shell window.