Why should an NTP client maintain connections to several NTP servers?

A.
To receive NTP information every second as each server transmits NTP pings every five
seconds only.

B.
To improve the precision of the time by comparing responses from several servers.

C.
To not overload the remote server in case the local NTP time cache is not enabled.

D.
To not lose contact with all NTP servers in case the client changes networks.

Explanation: