What are the conditions for an aircraft to prevent unauthorized access?

The correct choice outlines the essential conditions that must be met to ensure an aircraft is effectively protected from unauthorized access. When an aircraft is attended, it means there is personnel present to oversee the area, which acts as a deterrent to any unauthorized individuals. Guarded refers to the use of security personnel or systems to protect the aircraft from external threats. Monitored indicates that surveillance systems are in place to continuously observe the area around the aircraft, enabling prompt responses to potential breaches. Sealed implies that the aircraft is secured in a way that makes it difficult to access without proper authorization.

Overall, these conditions collectively create a robust security posture, ensuring that unauthorized individuals cannot easily gain access to the aircraft, thus enhancing the overall safety and security of aviation operations.