The correct answer is: B. cd ..
The cd command is used to change the current working directory. The .. is a special directory that refers to the parent directory. So, the cd .. command will change the current working directory to the parent directory.
The cd command can also be used to change to a specific directory. For example, the cd /home/user command will change the current working directory to the /home/user directory.
The chdir command is another command that can be used to change the current working directory. However, the chdir command is not as commonly used as the cd command.
The cd command is a built-in command in most shells. This means that the cd command is available without having to install any additional software.
The cd command is a very useful command that can be used to navigate the file system.