单项选择题

A.On Server2, run the Certutil tool.
B.On Server1, update the CEP Encryption certificate template.
C.On Server1, update the Exchange Enrollment Agent (Offline Request) template.
D.On  Server3,  set  the  value of the  HKLM\Software\Microsoft\Cryptography\MSCEP\  HashAlgorithm\HashAlgorithm registry key.