To debug this error, where in the authentication process could the solution be found?

A user cannot authenticate to SSL VPN. You have verified the user is assigned a user group and reproduced the problem, confirming a failed-login session. You do not see an indication of this attempt in the traffic log. The user is not using a client certificate for login.

To debug this error, where in the authentication process could the solution be found?
A . apache
B . admin
C . cvpnd
D . cpauth

Answer: C