A systems administrator is receiving tickets from users who cannot reach the application app that should be listening on port 9443/tcp on a Linux server.
To troubleshoot the issue, the systems administrator runs netstat and receives the following output:

Based on the information above, which of the following is causing the issue?

A. The IP address 0.0.0.0 is not valid.
B. The application is listening on the loopback interface.
C. The application is listening on port 1234.
D. The application is not running.