A user will be traveling for a long duration and wants to be able to work for as much of the time as possible. Which of the following features would be BEST for the user to enable?

Bluetooth is a wireless communication feature that consumes battery power, and keeping it enabled would reduce, not extend, the working time.

Airplane mode disables all wireless communication features (Wi-Fi, Bluetooth, cellular, GPS) on a device. By turning off these power-intensive radios, it significantly conserves battery life, allowing the user to work for a longer duration while traveling.

"Wireless" is a general term for features like Wi-Fi and cellular data; keeping these enabled consumes significant battery power and would reduce working time.

A keyboard backlight consumes battery power and offers no benefit to extending the duration a user can work, especially if the goal is power conservation.