Which element of a web application deployment descriptor  element is required（）？

A. authorization
B. data integrity
C. confidentiality
D. authentication

A. j_login
B. j_get_user
C. j_login_check
D. j_get_security
E. j_security_check

A. the URL pattern that requires authorization
B. the HTTP methods that require authorization
C. the users allowed access to the web resource
D. the J2EE roles allowed access to the web resource
E. the authentication mechanism required by the web resource