Hi there!
To make steel, you have to find iron of course. You melt the iron and you add... um, carbon if I'm correct?
I think that is correct. The crazy thing about steel is, it is like a sponge - there's a special bar of "soap" made from steel and you can rub it on your armpits to take away the smell. When I had finished cutting up an onion, I rubbed my hands on my kitchen sink, made from steel, and it soaked up the smell, like a sponge. It has something to do with the iron in it.
From the answer choices you posted I would go with either A or C... maybe C is correct.
Hope this helps!