For security reasons, the system administrator is setting up a log server.

What file does the system administrator have to edit in order to have each machine send log entries to the new log server?

Answer: /etc/syslog.conf

Explanation:
From the man pages:
The syslog.conf file is the main configuration file for syslogd(8) which logs system messages on *nix systems. This file specifies rules for logging.