What defines a noncombustible material?

A noncombustible material is defined as one that does not support combustion when exposed to fire. This means that these materials will not ignite or contribute to the fire, making them ideal in construction and safety applications where fire resistance is essential. Noncombustible materials can be essential for preventing the spread of fire and protecting other structures and materials from igniting.

In the context of the question, the other options do not correctly describe noncombustible materials. A material that can catch fire easily or one that ignites under high temperatures indicates a combustibility risk rather than resistance to combustion. Similarly, a material that burns with a flame contradicts the definition of noncombustible, as such materials would actively support combustion. Therefore, the accurate characterization of noncombustible materials is that they do not support combustion when exposed to fire, making the selected answer correct.