What is the minimum required radius for non-splitting or non-bursting comets and mines?

The minimum required radius for non-splitting or non-bursting comets and mines is established based on safety considerations to protect spectators and property from potential hazards associated with fireworks displays. Comets and mines typically produce effects that can lead to a risk of debris or fire, and the NFPA 1123 code specifies a minimum distance to create a safe viewing area.

The value of 35 feet/inch reflects the NFPA guidelines designed to ensure that the audience remains at a safe distance from these types of aerial devices during the display. This distance is determined not only by the physical height and nature of the effects but also by historical data and safety practices developed from past incidents. This standard aims to prevent injuries and damage while allowing for an optimal viewing experience.

The other options do not conform to the established safety distance recommended by the NFPA for this category of fireworks, thus making 35 ft/in the correct choice.