Inform-basedauthentication,whatmustbeincludedintheHTMLreturnedfromtheURLspecifiedbytheelement?()
A.abase-64encodedusernameandpassword
B.aformthatPOSTstothej_security_checkURL
C.anappletthatrequeststheusernameandpasswordfromtheuser
D.ahiddenfieldthatsuppliesthelogin-constraintusedbytheapplication