Electrolytic refining is used to purify which of the following metals?

Electrolytic refining is used to purify less reactive metals like Cu, Zn, Au, Ag etc…

In electrolytic refining, the impure metal is made the anode and the pure metal is made the cathode. A suitable electrolyte is chosen and electricity is passed. The impure metal dissolves at the anode and the insoluble impurities are collected as anode mud, while the pure metal gets deposited at the cathode. Metals of very high purity are thus obtained by electrolytic refining.