Which action must you perform to use CRLs to validate user certificates?

A.
Configure an OCSP responder.

B.
Validate a trusted server CA.

C.
Import as a trusted client the root certificate of the CA issuing the CRL.

D.
Configure a CA chain.

Explanation:
http://www.juniper.net/techpubs/en_US/sa/topics/reference/general/secure-accesscertificates-certificate-revocation-about.html