Which of the following statements about various authentication mechanisms in J2EE are true?

The FORM based authentication requires a user to possess a Public Key Certificate.

The realm string of the BASIC authentication must reflect a security policy.

In case of the CLIENT-CERT authentication, a base-64 encoded user name and password is used.

The DIGEST authentication may or may not be supported for a J2EE 1.4 compliant Web container.