Answer:
A. OCSP
Step-by-step explanation:
Online Certificate Status Protocol (OCSP) is an Internet Protocol that is used as an alternative for CRL and is used to obtain the revocation status of a digital certificate.
A certificate revocation list (CRL) is a set of digital certificates that have been rendered invalid/revoked by the Certificate Authority (CA) because they can no longer be trusted.
Because an OCSP response uses less data than a CRL, it would be best suited to the administrator's needs.