Which security mechanism is employed only on the server-side to limit access to resources or components？（）

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

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