clarification on mock exam question

[Chandra Sagi]

Which authentication mechanism is recommended to be used only if cookies or SSL session tracking is in place?

A) HTTP Basic Authentication
B) Form Based Authentication
C) HTTP Digest Authentication
D) HTTPS Client Authentication

The answer in the books says B), could anyone explain me why?

Thanks in advance
Chandu

[Sue Pillai]

In case of the other three you just include the <auth-mathod> element in the <login-config> in the DD and that is it. The container takes care of everything else. But, in the case of form-login, if you do not have session-tracking or cookies or SSL, the container will not recognize the client in subsequent transactions.

[Chandra Sagi]

Sue,

Thanks for your reply

Chandu