That seems to have been changed for some people. I have such an option when I run Nautilus as my normal user, but not when I run it as root. I don't know what's different.
Originally Posted by perspectoff
The checkbox "Allow executing file as program" seems to be relevant here, but but I'm not sure what it means. Nautilus clearly is inventing their own terminology rather than using the terminology everybody else uses.
You can make it setuid from the terminal like this:
Read for an explanation of what those numbers mean.
sudo chmod 4755 /usr/lib/cups/backend/cups-pdf