Which of the following is a commonly used proword?

• A. ARRIVE
• B. CONFIRM
• C. OVER
• D. TRANSMIT

Answer: (C)

In radio communications, prowords are standardized short phrases used to manage the flow of dialogue and keep messages clear. A commonly used proword is the one that signals you have finished speaking and are awaiting a reply. That's why this term is the best choice: it directly indicates turn-taking and invites the other station to respond, which helps prevent talking over each other and keeps the exchange efficient, especially in noisy or high-pressure environments.

Other words here aren’t prowords for ending a transmission. Arrive is just a regular word with no specific radio-communication function. Confirm is more of a request or action in plain language, not a designated proword for signaling the end of your turn. Transmit is a directive about sending data, not a cue to yield the floor to the other party.