Concept:The residual solid from petroleum fractional distillation is mainly bitumen or asphalt.
Explanation:During fractional distillation of petroleum, the volatile fractions are collected at different temperatures.
The thick, non-volatile residue left behind is the solid bitumen.
Bitumen is commonly used for road surfacing, roofing, waterproofing, and for coating pipes to prevent corrosion.
The residue is not used as a raw material for cracking; cracking uses fractions like naphtha and kerosene.
Tractor fuel is diesel oil, and jet engines use kerosene, neither of which is the residual solid.
Therefore, the best description among the options is coating of pipes.
Answer:A. coatings of pipes