Coke is defined as:

• A. Fuel with many impurities and 50% carbon content
• B. Fuel with few impurities and 98% carbon content
• C. Ore containing iron
• D. A type of limestone

Answer: (B)

Coke is a high-carbon fuel produced from coal by heating it in a restricted air environment, which drives off volatile components and leaves mostly carbon with very few impurities. In ironmaking, coke provides both heat and a reducing atmosphere, so having a high carbon content and low impurities is essential for efficient smelting and clean metal. That’s why the best description is a fuel with few impurities and a very high carbon content, around the high 90s. The other choices don’t fit because coke isn’t an iron ore, isn’t limestone, and isn’t a fuel loaded with impurities or only moderate in carbon.