Which JSTL tag structure supports this scenario？（）

单项选择题Assuming the tag library in the exhibit is imported with the prefix forum， which custom tag invocation produces a translation error in a JSP page？（）

A.A
B.B
C.C
D.D
E.E

单项选择题Whichthe securitymechanismusestheconceptofarealm？（）

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