Why can't I change the security method in acrobat reader dc

Hello,

Every time I open a pdf with my Adobe Acrobat Reader and attempt to change the security settings so that I can make a document "unprintable," the security method simply reads as "no security." There's not even a drop down box. I've reinstalled it and switched from the plain adobe reader but nothing has worked.

I'm working with Windows 10.

Thank you in advance.