Which entry in this server’s NTP configuration file indicates undisciplined local clock usage?

The IP address of an NTP Stratum 4 server is 192.168.30.30. Which entry in this server’s NTP
configuration file indicates undisciplined local clock usage?

A.
server 192.168.30.30

B.
server 127.127.1.0 prefer

C.
server 192.168.30.30 local

D.
server 127.127.1.0 local