What are the 6 methods available for user authentication?

What are the 6 methods available for user authentication?
A . Local Database: The user name and password in their user record in the instance database.
B. Multifactor: The user name and password in the database and passcode sent to the user’s mobile device that has Google Authenticator installed
C. LDAP: The user name and password are accessed via LDAP in the corporate directory, which has a matching user account in the database.
D. SAML 2.0: The user name and password configured in a SAML identity provider account, which has a matching user account in the database.
E. OAuth 2.0: The user name and password of OAuth identity provider, which has a matching user account in the database.
F. Digest Token: An encrypted digest of the user name and password in the user record.

Answer: A,B,C,D,E,F