Hi,
correct answer is "BUBBUB"
First B: for session.setAttribute("dab", new DealerAddrBean());
Next UB-> B: for session.setAttribute("dab", new DealerAddrBean());
As it is replacing the same attribute dab..
Next UB: for session.setAttribute("dab","x");
As it is removing existing DealerAddrBean (Unbind is called). Since it is not binding DealerAddrBean but its placing a string, no valueBound method is called.
session.removeAttribute("dab"); is not printing anything because it is removing attribute where value is String.. and it does not have valueUnbound() method.
Hope this helps you.
Regards,
Swathi.