Smelting is usually carried out in

The Smelting is a process in which the base metal is extracted from the ore by applying heat to it. It is one kind of extractive metallurgy. It is used for the extraction of many metals like copper, aluminium, iron, silver, lead and many other base metals from their respective ores. 

It is a process that involves heating raw materials in a furnace, blast furnace, or smoker to produce refined commodities. 

Therefore, Smelting is usually carried out in a Blast furnace.

Hence, option(A) is the answer.