Which interface must a class implement so that instances of the class are notified after any object added to a session?

Which interface must a class implement so that instances of the class are notified after any object added to a session?

A.
javax.servlet.http.HttpSessionListener

B.
javax.servlet.http.HttpSessionValueListener

C.
javax.servlet.http.HttpSessionBindingListener

D.
javax.servlet.http.HttpSessionAttributeListener