Cast iron is used for the manufacture of :

Solution

Chemistry ma’am · 3 steps

Follow the carbon downhill: pig iron makes cast iron, and cast iron makes the purer irons.

1. Start at the furnace. Iron from the blast furnace is pig iron, with about 4% carbon and other impurities. Remelting pig iron with scrap iron and coke under a hot air blast gives cast iron, with slightly less carbon (about 3%).

   Form of iron	Carbon content	Made from
   Pig iron	about 4%, highest	the blast furnace
   Cast iron	about 3%	pig iron + scrap iron + coke
   Steel	lower, controlled	cast iron
   Wrought iron	lowest, purest commercial iron	cast iron, in a haematite-lined reverberatory furnace

2. Going purer. To get wrought iron, the carbon and other impurities in cast iron are oxidised in a reverberatory furnace lined with haematite. Steel is also made from cast iron by bringing its carbon down to a controlled amount.
3. So. Cast iron is used to make wrought iron and steel, which is option (c). Pig iron and scrap iron are what go into cast iron, not what come out of it.

The idea to keep. Remember the order pig iron, then cast iron, then steel and wrought iron, with carbon falling at each step. Anything earlier in the chain is a raw material, never a product.

Answer from the NTA final answer key. Solution by PrepWiser.