Which interface must a class implement so that instances of the class are notified after any object is addedto a session？（）

A.Create an HttpSessionListener class and implement the sessionInitialized method with that block ofcode.
B.Create an HttpSessionActivationListener class and implement the sessionCreated method with thatblock of code.
C.Create a Filter class， call the getSession（false） method， and if the result was null， then execute that block of code.
D.Create an HttpSessionListener class and implement the sessionCreated method with that block of code.

A.To manage the user’s login and logout activities.
B.To store information on the client-side between HTTP requests.
C.To store information on the server-side between HTTP requests.
D.To tell the web container to keep the HTTP connection alive so it can make subsequent requestswithout the delay of making the TCP connection.

A.Tag files can only be accessed using a tagdir attribute.
B.The sort.jsp page translates successfully and invokes the tag defined by beta.tag.
C.The sort.jsp page produces a translation error because a taglib directive must always have a uriattribute.
D.Tag files can only be placed in /WEB-INF/tags， and NOT in any subdirectories of /WEB- INF/tags.
E.The tagdir attribute in line 2 can be replaced by a uri attribute if a TLD referring to beta.tag is createdand added to the web application.