Which statements are true about the Network Time Protocol (NTP)? (Select two.)

A.
It can deliver time-stamped messages via a multicast delivery system.

B.
It delivers time-stamped messages using TCP to port 123.

C.
The most precise time source is a stratum level 16 clock.

D.
Timestamps can be digitally signed with certificates.

E.
Timestamps can be digitally signed for verification.

Explanation: