The correct answer is: D. Wrought iron
Wrought iron is the purest commercial form of iron. It is made by repeatedly heating and hammering molten iron until the impurities are removed. Wrought iron is a very strong and ductile material, and it is often used in making decorative ironwork and other items that require a high degree of strength and flexibility.
Pig iron is a type of iron that is produced in a blast furnace. It is a very impure form of iron, and it contains a high percentage of carbon. Pig iron is used to make steel.
Steel is an alloy of iron and carbon. It is a stronger and more durable material than pig iron. Steel is used to make a wide variety of products, including cars, buildings, and appliances.
Stainless steel is a type of steel that is resistant to
corrosion. It is made by adding chromium to steel. Stainless steel is used to make a variety of products, including kitchen appliances, cutlery, and jewelry.