What two words may be used to interrupt a lower priority interphone message?

The correct response highlights the critical terms "EMERGENCY" and "CONTROL" as the established phrases for interrupting a lower-priority interphone message. This is essential in air traffic control communications, where the clarity and urgency of messages can be crucial for safety and operational efficiency.

Using "EMERGENCY" signifies a situation that requires immediate attention and action, prioritizing communication in potentially hazardous scenarios. Similarly, “CONTROL” emphasizes the necessity of direct oversight from a controller, indicating that the communication is vital for maintaining safety and compliance within the airspace. These terms are specifically designed to ensure that such interruptions are easily recognized, facilitating swift and proper responses.

In contrast, other options may represent common words or phrases used in communication, but they do not carry the same level of urgency or have specific protocols associated with them for interrupting messages. Hence, "EMERGENCY" and "CONTROL" are the appropriate and preferred choices for effectively managing interruptive communications in this high-stakes environment.