You work as the enterprise exchange administrator at Company.com.The Company.com network consists of a single Active Directory domain named Company.com.Company.com has an Exchange Server 2010 organization.the Company.com contains an exchange server 2010 client access server named -ex19.you have received instructions from the cio to set up certificates to support the following： Auto discover outlook anywhere exchange active sync.What should you do？（）

• A、the best option is to reissue a self-signed certificate to -ex19.
• B、The best option is to set up the default Web site to require SSL.
• C、The best option is to issue a trusted certificate that has multiple subject alternate names.
• D、The best option is to install Active Directory Rights Management Service （AD RMS） on a member server.