What other information is needed to join the existing vCenter Single Sign-On domain?

An administrator is deploying a vCenter Server Appliance and wants to join an existing vCenter Single Sign-On domain.
The administrator gathers the following information:
FQDN of the vCenter Single Sign-On server to join
Domain name of the vCenter Single Sign-On server being joined
Password of the vCenter Single Sign-On server administrator account.
What other information is needed to join the existing vCenter Single Sign-On domain? (Choose the best answer.)
A. vSphere Client port
B. Lightweight Directory Access Protocol (LDAP) port
C. Single Sign-On (SSO) port
D. HTTPS port