Multiple choice chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes Poling process: reduces $SnO _2$ to Sn oxidizes impurities like iron and removes as scum uses green poles uses brown poles Reveal answer Fill a bubble to check yourself A,B,C Correct answer Explanation Poling: A refining process of crude metal for removing metal oxide impurities by stirring molten metal in a ladle with a pole of green wood (poles). In the poling process, the reduction of oxides to metal atom will be done. Ex: Extraction of copper from copper oxide and Sn from $SnO _2$. Hence options A,B & C are correct.