Which of the following equipment checks occurs during preflight?

The checks performed during preflight play a crucial role in ensuring the safety and security of passengers and crew. One key aspect of these checks is the inspection of emergency equipment. This includes verifying that all safety gear, such as life vests, oxygen masks, and first aid kits, is on board, properly stowed, accessible, and functioning correctly. Ensuring that emergency equipment is in optimal condition is essential, as it prepares the crew to effectively respond to any potential emergencies during the flight.

Although passenger boarding procedures, security camera checks, and seat configuration reviews are important aspects of overall operational readiness, they do not focus solely on the critical safety equipment that is specifically addressed in preflight checks. Thus, emergency equipment checks stand out as a vital element in maintaining safety standards, which is why it is the correct answer.