The correct answer is Cathode: pure silver; anode: impure silver; electrolyte: AgNO3 (aq).Concept:Electrolytic refining:It is a process of refining (removing impurities or other elements) a metal by the process of electrolysis.Electrolysis: It is the process that uses electric current to run a non-spontaneous chemical reaction.The passage of electric current through a chemical compound causing the decomposition of the compound is called electrolysis.During electrolysis, Positively charged ions move towards the cathode and negatively charged ions move towards the anode.Electrolytes:Compounds that undergo ionization and conduct electricity in the molten or dissolved state are called electrolytes.Explanation:Electrolytic refining of Metals:In this process, the impure metal is made into the anode and a thin strip of pure metal is made into the cathode.The solution of the metal salt is used as an electrolyte.When current passes through the electrolyte, the pure metal from the anode dissolves into the electrolyte.An equivalent amount of pure metal from the electrolyte is deposited on the cathode.The insoluble impurities settle down at the bottom of the anode and are known as anode mud whereas the soluble impurities go into the solution.So, for electrolytic refining of Silver following set-up will be needed:Cathode - Pure silverAnode - Impure silverElectrolyte - Salt of Silver like AgNO3 (aq)