Which of the following actions is NOT part of maintaining passenger comfort?

Controlling aircraft navigation is primarily the responsibility of the flight crew, specifically the pilots, and does not directly concern passenger comfort. The job of a flight attendant revolves around ensuring that passengers have a pleasant and comfortable experience during their flight. Actions such as regulating cabin temperature create a suitable environment, providing refreshments caters to passengers' needs for food and drink, and addressing passenger concerns ensures that any issues that may arise are handled promptly for a better flying experience. Each of these actions directly impacts how comfortable and satisfied passengers feel during their journey, whereas aircraft navigation is focused on the safety and operational aspects of flying, which, while critical, does not fall under the category of passenger comfort.