LDAP (Lightweight Directory Access Protocol) is used to query and retrieve user credential information from a directory service (like Microsoft Active Directory).

It’s not an authentication protocol itself but is used by services like RADIUS to validate user credentials during the EAP authentication process.

Incorrect:

B. LDAP is not directly compliant with X.500—it uses a simplified subset.

C. LDAP is not a SQL-compliant protocol.

D. LDAP is not a role-based access control mechanism.

E. LDAP is not an Authentication Server by itself.