Which command is used to make all files and sub-directories in the directory (progs) executable by all users? A. chmod -R a+x progs B. chmod -R 222 progs C. chmod -1 a+x progs D. chmod -x a+x progs E. None of the above

The correct answer is A. chmod -R a+x progs.

The chmod command is used to change the permissions of a file or directory. The -R flag tells chmod to apply the changes recursively to all files and subdirectories in the specified directory. The a+x flag tells chmod to make the file or directory executable by all users.

Option B, chmod -R 222 progs, would make the file or directory executable by the owner and group, but not by other users. Option C, chmod -1 a+x progs, would make the file or directory unreadable by all users. Option D, chmod -x a+x progs, would make the file or directory executable by the owner, but not by group or other users.

Here is an example of how to use the chmod command to make all files and subdirectories in the directory progs executable by all users:

chmod -R a+x progs

This command would make all files and subdirectories in the directory progs executable by all users.