Which statement regarding combustion is correct? -A solid fuel must be heated to its flash point for combustion to occur.
-The time required to ignite a fuel is a function of the heat of combustion.
-Solids do not burn; they decompose and release combustible vapors that burn.
-No reaction between a fuel and oxidizer is required for combustion.

I think the first one

Explanation:

rapid chemical combination of a substance with oxygen, involving the production of heat and light.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.