The correct option is
B A - I, B - II, C - IV, D - III
A. Van-Arkel method: This method is used for ultrapure metal like Ti, Zr etc. The metal is converted into its volatile stable compound such as TiI4, leaving behind impurities. The stable volatile compound thus formed is decomposed to get pure metal.
Ti(impure)+2I2500k−−→TiI41675K−−−−→Ti+2I2(pure)
B. Solvay process: The Solvay Process, used in the manufacture of Na2CO3 is a continuous process using limestone (CaCO3) to produce carbon dioxide (CO2) which reacts with ammonia (NH3) dissolved in brine (concentrated NaCl(aq)) to produce sodium carbonate.
C. Cupellation: Pb present in Ag is removed by this method. The impure metal is heated in a cupel or oval-shaped crucible made of bone ash or cement and the blast of air is passed over the molten mass. The impurities get oxidized and removed with the blast of air.
D. Poling: The molten impure metal (Cu) containing oxides as impurities are stirred with green poles of wood which releases hydrocarbon gases. The hydrocarbon gases reduce oxide to metal.
A - I, B - II, C - IV, D - III
Option A is correct.