Which two options are correct about SSO? (Choose two)

A.
In order to accomplish SSO, all application systems need to share one authentication system

B.
In order to accomplish SSO, all application systems need to be able to identify and collect ticket information.

C.
It is needed to have a single database of user information

D.
Only a single authentication server can be used as a unified authentication system

Explanation:
SSO in this context means Single Sign On, not Stateful Switch Over ^^