TestOut Linux Pro Practice Test

Using the command `ls -l` is an effective way to confirm that the directory structure of the White Horse project has been removed. The `ls` command lists the contents of a directory, and when used with the `-l` option, it provides detailed information in a long format, such as permissions, ownership, size, and modification date about each item in the directory.

After trying to remove the directory structure, if you run `ls -l` in the parent directory, you will see whether the White Horse project directory and its contents still exist. If they have been successfully removed, there will be no output related to the White Horse project, confirming that the operation was successful.

The other methods have limitations: manually checking the /home directory does not provide an efficient way to confirm the absence of the project; using the `rm` command is for removing files or directories rather than confirming their removal; and the `pwd` command simply displays the current working directory without providing information about its contents.