In radio communication, what should you say if you want to indicate you have finished speaking and are awaiting a response?

In radio communication, saying "Over" signifies that you have finished your transmission and are awaiting a response from the other party. It's a standard protocol used to clearly indicate that you have completed your message and are expecting an acknowledgment or further communication. This term is widely recognized in marine and aviation communication to ensure clarity and prevent misunderstandings.

The other options do not serve this purpose. "End of message" is not a common term used in radio communication. "Affirmative" is used to confirm a statement or agreement but doesn’t indicate a transition for the other party to respond. "Copy that" indicates understanding but does not communicate that you are finished speaking. Therefore, “Over” is the appropriate term to use when you want to signal that your communication is complete and you're ready for the other person to reply.