In which of the following isolations is no reducing agent required?

$Ag_2S + NaCN + Zn \rightarrow Ag$
This method of extraction of $Ag$ by complex formation and then its displacement is called:

The purpose of smelting in metallurgy is ...........

Among the following,an example of the thermite process is:

$Ni$ anode is used in the electrolytic extraction of

Statement $I :$ Leaching of gold with cyanide ion in absence of air $/$ $O_2$ leads to cyano complex of $Au(III)$.
Statement $II :$ Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements,choose the correct answer from the options given below.