How Did Iron Become the Basic Building Block of the British

How did iron become the basic building block of the British economy in the nineteenth century?

A) The spread of coke smelting and the development of steam-powered rolling mills increased production enormously and reduced the price of iron products.
B) Government-funded research led the way in the development of inexpensive processes for the production of iron products.
C) British capitalists used new techniques developed in American iron foundries to increase the manufacture of inexpensive iron products.
D) Breakthroughs in Russian iron production dramatically lowered the price of iron early in the nineteenth century.