What is the aviation security measure that involves screening passengers and baggage?

The aviation security measure focusing on the screening of passengers and baggage is essential for maintaining safety within airports and on aircraft. This process involves thorough checks to identify any prohibited items or potential threats that could compromise security. Passenger and baggage screening includes practices such as using metal detectors, X-ray machines, and manual inspections, thereby ensuring that both individuals and their luggage are safe before boarding.

This measure plays a critical role in minimizing the risk of incidents during air travel by proactively identifying and mitigating potential security threats. It is a standard procedure in airports worldwide and is essential for regulatory compliance and passenger confidence in air travel safety.

In contrast, the other options refer to different safety or operational measures. A pre-flight inspection pertains to checks on the aircraft itself before departure, not on passengers or their baggage. A load distribution check deals with the proper distribution of cargo and passengers within an aircraft to ensure balance and stability rather than security. An emergency evacuation drill is crucial for ensuring preparedness in the event of an incident but does not specifically address the screening processes prior to flight. Thus, the passenger and baggage screening process is the clear and direct answer to the question of which aviation security measure involves these critical assessments.