What proword indicates the end of a transmission and requests a response?

The term that indicates the end of a transmission and requests a response is "over." This proword is used in radio communication to signal that the speaker has finished their transmission and is expecting a reply from the recipient. By using "over," the communicator establishes a clear protocol, ensuring that both parties understand when to talk and when to listen. This is crucial in maintaining effective communication in combat scenarios, where clarity and brevity can significantly impact operations.

"Clear" is often used to indicate that a channel or area is free of obstacles or threats, while "roger" communicates that a message has been received and understood, but it does not imply a need for a response. "Copy" acknowledges that the message was received, but similar to "roger," it doesn't indicate that a response is necessary. Therefore, "over" is the most appropriate choice for signaling the end of a transmission while prompting a reply.