Answer:
correct option is B. Primer residue
Explanation:
correct answer is Primer residue because primer residue are form from the ignition of the chemicals in primer when the firearm is discharge
and the result in formation of microscopic particle that is blown out of various opening in weapon when this weapon is discharge
and this primer residue is deposit on hand as firing weapon and hand weapon
but in the absence of primer residue on hand it is consistent with individual not have fire
so correct option is B. Primer residue
They needed people to work the factories with the men are gone to war.