The correct answer is: A. Cast iron
Cast iron is a type of iron that contains a high percentage of
carbon. It is a hard and brittle material that is used in a variety of applications, including castings, machine tools, and cookware.Stainless steel is a type of steel that contains a high percentage of chromium. It is a corrosion-resistant material that is used in a variety of applications, including appliances, cookware, and building materials.
Wrought iron is a type of iron that contains a low percentage of carbon. It is a soft and ductile material that is used in a variety of applications, including nails, chains, and wire.
High speed steel is a type of steel that contains a high percentage of tungsten. It is a hard and wear-resistant material that is used in a variety of applications, including cutting tools and dies.
The percentage of carbon in each of these materials is as follows:
- Cast iron: 2.1-4.5%
- Stainless steel: 0.08-2.0%
- Wrought iron: 0.02-0.08%
- High speed steel: 1.0-12.0%
As you can see, cast iron has the highest percentage of carbon. This is why it is a hard and brittle material.