Let us assume that you are the chief security officer for an organization that requests you to implement an access control system for all their data. Under the access control model, you will propose, a) which of the following entities would exist as an object; and b) and which would exist as a subject? You must give a small justification for each answer.

a) A file; b) A User; c) A Printer; d) A Router; e) A Group of Users