TOEFL Listening: TPO-TOEFL阅读TPO - FRKJ7744DCK24484N$

According to paragraph 3, why was the use of coke important for the iron industry? A. It helped make wood into charcoal. B. It reduced the dependency on steam-powered machines used for the production of iron. C. It replaced charcoal in the production of raw and refined iron. D. It powered the machines used to extract coal in coal mines.