Which situation requires immediate reporting to the cockpit by the flight attendant?

The necessity for immediate reporting to the cockpit by a flight attendant arises from situations that may compromise the safety of the flight. Suspicious behavior of a passenger is a critical concern as it could indicate a potential security threat or a disruptive situation that might escalate. Flight attendants are trained to be vigilant and to recognize signs that could threaten the safety or security of the aircraft and its passengers. In such instances, promptly informing the cockpit crew allows for appropriate and timely responses, which could involve heightened security measures or coordination with ground authorities.

In contrast, passenger dissatisfaction with seating arrangements, technical difficulties with the in-flight entertainment system, and delays in meal service, while they may impact passenger experience and comfort, do not pose immediate safety risks. Such issues can typically be resolved by the cabin crew without the urgent need for cockpit involvement.