Your network contains an enterprise root certification authority （CA）. You need to ensure that a  certificate issued by the CA is valid.     What should you do（）

• A、Run syskey.exe and use the Update option.
• B、Run sigverif.exe and use the Advanced option.
• C、Run certutil.exe and specify the -verify parameter.
• D、Run certreq.exe and specify the -retrieve parameter.