Which proword indicates a need for the receiver to pause before responding?

The proword that indicates a need for the receiver to pause before responding is "Stand By." This term is commonly used in radio communication to instruct the recipient to wait for further instructions or clarification before proceeding. By using "Stand By," the sender is effectively signaling that they need a moment to gather information or communicate additional details, allowing for a more organized exchange of information.

In contrast, terms like "Negative" typically indicate denial or disagreement, "Affirmative" confirms the previous statement, and "Break" is used to separate transmissions or indicate a change in topic but does not specifically call for a pause before replying. Therefore, "Stand By" is the most appropriate choice for indicating a pause in communication.