Your company has a main office and a branch office. Your network contains a single Active Directory domain. You install 25 Windows Server 2008 R2 member servers in the branch office. You need to recommend a storage solution that meets the following requirements： èEncrypts all data on the hard disks èAllows the operating system to start only when the authorized user is present What should you recommend？（）
- AEncrypting File System （EFS）
- BFile Server Resource Manager （FSRM）
- CWindows BitLocker Drive Encryption （BitLocker）
- DWindows System Resource Manager （WSRM）