You work as the exchange administrator at TestKing.com. The TestKing.com network contains anExchange Server 2010 Organization. A new TestKing.com security policy requires that smart cardauthentication be used for all connections to Outlook Web App （OWA）. During the course of day you receive an instruction form the CIO to recommend a solution to management that will comply with the new security policy. What should you do？（）

• A、You should recommend that an Edge Transport server be deployed.Thereafter Windows Integrated authentication should be disabled.
• B、You should recommend that a certificate-based authentication be required for all Internet-facing Client access servers.
• C、You should recommend that a server that is configured to run Microosft Internet Security and acceleration （ISA）Server be deployed.Thereafter Kerberos contrained delegation should be enabled.
• D、You should recommend that Windows Integrated Authentication be compulsary for all Internet-facing client Access servers.