Answer:
B. Mixture
Step-by-step explanation:
Steel is an example of a mixture. It's known as an alloy of iron mixed with carbon. The carbon helps to improve its strength and its resistance to fracture. Other percentages of chromium, nickel, vanadium, etc can be added in order to obtain steels of a desired hardness, resistance to corrosion, etc. Due to its high tensile strength, it is used in tools, ships, cars, electrical appliances, weapons, etc.
Please note: I answered this question with my knowledge of steel and to the best of my ability. The passage that was referred to in the excerpt wasn't added for me to use.