The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, and Linux.
Answer:
C is the answer to this question.
When a document repository is down when you attempt to access it, the ISA principle Authentication is being violated. The authentication method is done during the log on phase and is performed by the ISA server which requests certificate. <span>The client then needs to send the appropriate client certificate to the server in order to be authenticated and to have access to the document.</span>
