What should the "A" flight attendant hear from pilots after hearing 4 high-low chimes?

The appropriate response to the "A" flight attendant after hearing 4 high-low chimes should indeed be TNT, which stands for Time, Notification, and Type of emergency. This alert system is critical in aviation safety protocols, as it provides flight attendants with essential information required to respond appropriately in the event of an emergency situation.

The significance of TNT lies in its structured approach: the "Time" component ensures that attendants understand the urgency and timing of the situation, "Notification" informs them of the nature of the emergency, and "Type of emergency" specifies what kind of response is necessary. This ensures that flight attendants are fully informed and can prepare the cabin and passengers accordingly, which is crucial for maintaining safety and order during critical situations.

Other responses, while relevant in their contexts, do not align with the immediate need for emergency preparedness after the chime activates. Confirmation of departure time pertains primarily to pre-flight logistics, instructions for cabin checks focus on routine safety procedures, and emergency contact procedures are more about external communications rather than immediate cabin response. Thus, TNT is the logical outcome that aligns with the emergency communication protocol following the high-low chimes.