Which code provides acknowledgement of receipt?

• A. 10-23
• B. 10-9
• C. 10-4
• D. 10-8

Answer: (C)

Communicating efficiently over radio relies on standardized codes to close the message loop. Acknowledge receipt means you confirm you got the transmission and understand it. The code used for that purpose conveys “OK” or “message received.” That makes it the best choice because it provides a clear, unambiguous confirmation with minimal words, which is crucial in fast-paced operations to keep everyone on the same page.

The other options serve different roles: one is used when you need the sender to repeat the message, another signals that you are standing by for further instructions, and another indicates you are in service or available for assignments.