Comprehensive Detailed Explanation:

Pyrolysis is the chemical decomposition of solid materials (often organic) caused by heat. It results in the release of flammable gases or vapors, which can mix with oxygen and ignite. Pyrolysis is a critical process in the early stages of a solid-fuel fire.

Liquidity (A) and Vaporization (B) refer to liquids turning into gas, not solid decomposition.

“None of the above” (D) is incorrect since “Pyrolysis” is the correct term.