单项选择题

A.Firewalluserauthenticationprovidesanotherlayerofsecurityinanetwork.
B.FirewalluserauthenticationprovidesameansforaccessingaJUNOSSoftware-basedsecuritydevice.
C.Firewalluserauthenticationenablessession-basedforwarding.
D.Firewalluserauthenticationisusedasalastresortsecuritymethodinanetwork.