Which metals M is commonly used to displace Ag from Ag(CN)₂?

Cyanide is used in the extraction of silver and gold (Mac Arthur - Forrest process). Following initial crushing and concentration by froth flotation, the ore (crushed auriferous rocks in the case of gold) is leached using a diluted (0.4–7%) solution of sodium cyanide made alkaline by adding lime and kept stirred by an air current. A solution of silver (or gold) is formed as argentocyanide (or aurocyanide):

${\mathrm{Ag}}_2\mathrm{S}+4\mathrm{NaCN}\to 2\mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN}{)}_2\right]+{\mathrm{Na}}_2\mathrm{S}$

Silver is produced by a reaction with zinc:

$2\mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN}{)}_2\right]+\mathrm{Zn}\to {\mathrm{Na}}_2\left[\mathrm{Zn}(\mathrm{CN}{)}_4\right]+2\mathrm{Ag}$