The chmod command lets you change the permissions of a file or directory. It's short for "change mode" (I wish it was called "change permissions", but alas).
As part of your security audit, you need to know who has access to the files in the private directory. The ls command has a -l option (lowercase "L") that will print out the permissions of each file and directory in long format.
chmod -R u=rwx,g=,o= DIRECTORY
In the command above, u means "user" (aka "owner"), g means "group", and o means "others". The = means "set the permissions to the following", and the rwx means "read, write and execute". The g= and o= mean "set group and other permissions to nothing". The -R means "recursively", which means "do this to all of the contents of the directory as well".
Be sure to replace DIRECTORY with the path to the private directory.
Remember, . is a special alias for the current directory.
Paste only the 10-character permission string of the updated private directory itself (not its contents) into the input field and submit your answer.
If you're using WSL and chmod is not updating the permissions: your worldbanc directory may not be within your Linux subsystem. You can either move the directory or adjust your wsl.conf file to allow for editing permissions.