Given the following snoop trace:
sys4 -> sys10 NTP client [st=0] (2005-01-26 17:13:29.73040) sys10 -> sys4 NTP server [st=4] (2005-01-26 17:15:08.79499) sys4 -> sys10 NTP client [st=0] (2005-01-26 17:13:29.79606) sys10 -> sys4 NTP server [st=4] (2005-01-26 17:15:08.86071) sys4 -> sys10 NTP client [st=0] (2005-01-26 17:13:29.86199) sys10 -> sys4 NTP server [st=4] (2005-01-26 17:15:08.92638) sys4 -> sys10 NTP client [st=0] (2005-01-26 17:13:29.92734) sys10 -> sys4 NTP server [st=4] (2005-01-26 17:15:08.99198)
Why do the system clocks remain unsynchronized despite several queries?

A.
The NTP server daemon is disabled.
B.
The NTP client is configured as a broadcast client.
C.
The /etc/init/ntp.client file is misconfigured.
D.
The NTP client requires more updates from the NTP server.