Some pieces of pig iron on one side of the bath attracted my attention by remaining unmelted in the great heat of the furnace, and I turned on a little more air through the fire-bridge with the intention of increasing the combustion...Thus a new direction was given to my thoughts, and after due deliberation I became convinced that if air could be brought into contact with a sufficiently extensive surface of molten crude iron, it would rapidly convert it into malleable iron."

--From the Autobiography of Henry Bessemer, 1905
Which is the BEST description of how the Bessemer Process revolutionized the manufacture of steel?
A) The Bessemer Process made the steel lighter and easier to transport to far-away markets.
B) The Bessemer Process eliminated the use of coal in the manufacture of steel, which increased the profits of the steel mills.
C) The Bessemer process revolutionized the manufacture of steel by increasing the speed of its production and decreasing its cost.
D) The Bessemer Process allowed for the use of lower quality iron and coal, which in turn increased the profits of the steel mills.