Final answer:
Prewriting helps the sender of a business message identify the purpose, scope, and supporting points.
Step-by-step explanation:
Prewriting helps the sender of a business message identify the purpose, scope, and supporting points. By engaging in prewriting activities such as brainstorming, outlining, and organizing ideas, the sender can clarify their main objectives and determine the relevant information to include in the message. This ensures that the message is focused, well-structured, and effectively communicates the intended message to the receiver.