Without whom can the communication process not be completed?

The communication process cannot be completed without the receiver.

It is the receiver who decodes the message and, through feedback, closes the loop that makes communication whole.

Media is only a channel that carries the message and cannot by itself complete the exchange.

A writer may originate content but stands on the sending side, not the point where communication is completed.

An expert is merely a possible source of information and is not essential to completing the process.

Without a receiver to take in and respond to the message, no act of communication is finished.