Which two security features are available when implementing NTP? (Choose two)

Which two security features are available when implementing NTP? (Choose two)
A . symmetric server passwords
B . dock offset authentication
C . broadcast association mode
D . encrypted authentication mechanism
E . access list-based restriction scheme

Answer: D E

Explanation:

The time kept on a machine is a critical resource and it is strongly recommend that you use the security features of NTP to avoid the accidental or malicious setting of incorrect time. The two security features available are an access list-based restriction scheme and an encrypted authentication mechanism.