The following is my ntpd configure file. I have no idea, which one ntpd will choice while it's syncing?
/etc/ntp.conf server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server pool.ntp.org
The NTP daemon uses an algorithm that will evaluate the time returned by all the listed servers.
You can see it at work with the
NTP will look at the stratums, latency, and so on. It will select the server with the best time.
Since you are using pool.ntp.org entries and nothing else it really doesn't matter to much. It will select some server out of the pool.
Keep in mind that it will get time from the other servers as well to make sure that what it is getting from he master is not garbage. So it isn't exclusively using a single server.