Which proword indicates that a message has been received and understood?

The proword that indicates that a message has been received and understood is "Affirmative." This term is used in communication, especially in military contexts, to confirm clarity and agreement regarding the transmitted message. When someone responds with "Affirmative," it signifies that not only was the message heard, but also that the receiver comprehends its content, which is crucial for effective communication in operations where misunderstandings could lead to dangerous situations.

The other terms have different meanings that do not imply comprehension. "Break" typically signals a pause or separation in communication rather than acknowledgment of understanding. "Negative" is used to convey disagreement or rejection, indicating that the message has not been accepted. "Over" indicates that a speaker has finished their transmission and is awaiting a response, without confirming understanding of the previous message.