What is the purpose of the MQSC command 'DEFINE LISTENER'?

What is the purpose of the MQSC command ‘DEFINE LISTENER’?

What is the purpose of the MQSC command ‘DEFINE LISTENER’?
A . Establishes a channel for communication
B . Configures network settings for the queue manager
C . Defines a process for handling messages
D . Sets up a listener for incoming connections

Answer: B