Users Report That an Application Is Unable to Connect to a Server

Multiple Choice

Users report that an application is unable to connect to a server on the same network segment. Which of the following is the MOST likely reason?

A) The external firewall is preventing access to the server.
B) The DMZ is incorrectly configured.
C) The syslog server detects malware on the server.
D) The application is using a port that is closed on the server.