单选题Which protocol is used between the RAS and the authentication server in a narrowband network environment？（）A RADIUSB PPPPAPC MSCHAPD PPPCHAP
题目
单选题
Which protocol is used between the RAS and the authentication server in a narrowband network environment？（）
A
RADIUS
B
PPPPAP
C
MSCHAP
D
PPPCHAP