Which of the following is the purest form of carbon?

Coal gas Coal tar Coke None of the above

Coke

The correct answer is option 3. Coke. The purest form of carbon is coke, which is commonly made from coal. It is the solid carbonaceous byproduct of the destructive distillation of bituminous coal, which contains little ash and sulfur. In contrast, coal gas and coal tar have higher impurities and less carbon.