The correct answer is C. Message
Explanation:
In the process of communication, the message is considered as the main element. This answers to the question What is communicated?, or what is sent by the sender?. This implies the message is the communication/idea conveyed.
Moreover, this can be written or oral, and it includes the content (information), structure (organization of the information), and style (words and other elements used to transfer the information). For example, in newspapers the message refers to the information regarding current events, the organization is based on categories, the style is formal, and the content is facts, opinions, etc. about the events.