Which of the following can passengers use during flight below 10,000 feet?

Passengers are allowed to use pacemakers during flight below 10,000 feet because these medical devices are specifically designed for individuals who require them to manage heart conditions. Pacemakers are essential for monitoring and regulating heartbeats and are generally safe to use in all phases of flight, including during ascent and descent. Their use is critical for the health and well-being of those who depend on them, making it permissible under air travel regulations.

In contrast, items such as televisions, radios, and electronic smoking devices are typically subject to restrictions due to concerns over interference with aircraft systems and safety regulations. While personal electronic devices may have certain allowances depending on the airline and safety guidelines, pacemakers are recognized for their medical necessity and are exempt from such restrictions.