Which method is used to obtain ultra-pure copper?

The solubilities of the impurities in the melt and solid states are not the same. This principle is applied during the extraction of boron. This method is known as:

If a metal has low oxygen affinity,then the purification of the metal may be carried out by:

The extraction of nickel involves:

Which of the following methods is used for the refining of impure zirconium?

Given below are two statements.
Statement $I:$ During electrolytic refining,blister copper deposits precious metals.
Statement $II:$ In the process of obtaining pure copper by electrolysis method,blister copper is used to make the anode.
In the light of the above statements,choose the most appropriate answer from the options given below.