Which is a benefit of maintaining temperature and humidity in the ECS?

Maintaining temperature and humidity in the Environmental Control System (ECS) primarily enhances passenger comfort, which makes it the most relevant benefit among the options listed. A consistent and controlled environment ensures that passengers have a pleasant experience, helping to regulate factors such as thermal comfort and air quality inside an aircraft. When the ECS operates effectively in managing these conditions, it prevents discomfort related to temperature extremes, humidity, and overall air quality, which can significantly impact passenger satisfaction during flight.

While other options may touch on relevant considerations, such as fuel efficiency and maintenance aspects, the direct and primary purpose of the ECS is to create a comfortable environment for passengers. Enhancing comfort is crucial, especially on longer flights, where the quality of the cabin atmosphere can greatly affect the overall travel experience.