Which properties determine a material's flammability?

The properties that determine a material's flammability include its flash point, boiling point, and combustibility.

The flash point is the lowest temperature at which a substance can vaporize to form an ignitable mixture in air. This property is crucial because it helps to establish the conditions under which a material can catch fire, which is fundamental to assessing flammability.

The boiling point is the temperature at which a liquid turns into vapor. Understanding this property is important as materials that have a low boiling point can potentially be flammable at lower temperatures, thereby increasing the risk of combustion.

Combustibility refers to the ability of a substance to ignite and sustain a fire. This property encompasses various factors, including both the ease with which a material ignites and how readily it will continue to burn once ignited.

Overall, these three properties are integral in determining how a substance reacts in the presence of heat, making option B the correct answer, as it encompasses the critical factors needed to evaluate a material's flammability effectively.