What is asbestos?

Asbestos is a naturally occurring mineral fiber known for its unique properties, including high heat resistance, tensile strength, and chemical stability. These characteristics made asbestos a popular material in various industrial applications, including construction, insulation, and fireproofing, especially prior to the recognition of its health hazards. The mineral's fibrous structure allows it to be woven into textiles or mixed with other materials, enhancing their durability and fire resistance.

In contrast, the other options present materials or substances that do not accurately describe asbestos. For instance, synthetic materials used in construction refer to man-made products that may contain various chemicals or composites but are distinct from natural mineral fibers like asbestos. A harmful gas is not a relevant description, as asbestos itself is a solid material and does not exist as a gas. Lastly, the mention of plastic used for insulation also does not align with asbestos, which is an inorganic mineral rather than a synthetic polymer. Understanding these distinctions highlights why option A provides the correct definition of asbestos.