When the Spam Quarantine is configured on the Cisco ESA, what validates end-users via LDAP during login to the End-User Quarantine? 

Answer options:

A. Enabling the End-User Safelist/Blocklist feature
B. Spam Quarantine External Authentication Query
C. Spam Quarantine End-User Authentication Query
D. Spam Quarantine Alias Consolidation Query

C

Reference: https://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/118692-configure-esa-00.html