A(n) ____________________ model excludes users from access to resources, by default, and then adds whatever users need access to such resources as exceptions to the general exclusionary rule.

A(n)_____ performs administrative tasks such as creating and managing multiple applications using a tool found in some versions of mobile operating systems

Fill in the blank(s) with correct word

Sometimes it is advisable to offer a ________ app if there are numerous other apps with similar functionality.

A) freemium B) premium C) low-cost D) free