Correct Answer: Electrolytic Refining

Solution : The correct answer is Electrolytic Refining .

The most widely used method for refining impure metals is electrolysis. Electrolysis involves passing an electric current through a molten or dissolved ionic compound, causing the metal ions to migrate to the electrode (cathode), where they gain electrons and are deposited as pure metal. This method is commonly used for refining metals like copper and aluminium.