An organization is designing a large enterprise$-$wide document repository system. They plan tohave several different classification level areas with increasing levels of controls. The BEST way toensure document confidentiality in the repository is to:A$.$encrypt the contents of the repository and document any exceptions to that requirementB.utilize Intrusion Detection System $($IDS$)$ set drop connections if too many requests for documentsare detectedC.keep individuals with access to high security areas from saving those documents into lowersecurity areasD.require individuals with access to the system to sign Non$-$Disclosure Agreements $($NDA$)$