You have an Active Directory domain that runs Windows Server 2008 R2. You need to implement  a certification authority （CA） server that meets the following requirements：     - Allows the certification authority to automatically issue certificates  - Integrates with Active Directory Domain Services     What should you do（）

• A、Install and configure the Active Directory Certificate Services server role as a Standalone Root CA .
• B、Install and configure the Active Directory Certificate Services server role as an Enterprise Root CA .
• C、Purchase a certificate from a third-party certification authority. Install and configure the Active Directory Certificate S
• D、Purchase a certificate from a third-party certification authority. Import the certificate into the computer store of the sc