正解:D
Comprehensive and Detailed Explanation:
LDAP (Lightweight Directory Access Protocol) usesport 389for standard connections andport 636forLDAP over SSL (LDAPS), whichsecures directory service communication.
Breakdown of Options:
* A. 22- SSH port,not used for directory services.
* B. 389- Used forLDAP, butnot encrypted.
* C. 445- Used forSMB file sharing,not LDAP.
* D. 636-Correct answer.LDAPS (LDAP over SSL/TLS) secures directory authentication.