How does FortiGate verify the login credentials of a remote LDAP user?

How does FortiGate verify the login credentials of a remote LDAP user?
A . FortiGate regenerates the algorithm based on the login credentials and compares it to the algorithm stored on the LDAP server
B . FortiGate sends the user-entered credentials to the LDAP server for authentication
C . FortiGate queries the LDAP server for credentials.
D . FortiGate queries its own database for credentials.

Answer: B