The correct answer is: D. ls -a
The ls command lists the contents of a directory. The -a option tells ls to list all files, including hidden files. Hidden files are files whose names start with a dot (.).
The ls -l command lists the contents of a directory in long format. This includes the file name, permissions, owner, group, size, and modification date.
The ls -x command lists the contents of a directory in extended format. This includes the file name, permissions, owner, group, size, modification date, and links.
The ls -F command lists the contents of a directory with a special character for each type of file. For example, directories are listed with a /, regular files are listed with a -, and symbolic links are listed with an @.
None of the above options will list all the hidden files along with the other files.