What must be configured to enable RADIUS authentication with ClearPass on a network access device (NAD)? (Select two.)
A. the ClearPass server must have the network device added as a valid NAD
B. the ClearPass server certificate must be installed on the NAD
C. a matching shared secret must be configured on both the ClearPass server and NAD
D. an NTP server needs to be set up on the NAD
E. a bind username and bind password must be provided
A C are correct