Name the metal $M$ which is extracted on the basis of following reactions:
$4M + 8CN^{-} + 2H_2O + O_2 \rightarrow 4[M(CN)_2]^{-} + 4OH^{-}$
$2[M(CN)_2]^{-} + Zn \rightarrow [Zn(CN)_4]^{2-} + 2M$

• A
  Nickel
• B
  Silver
• C
  Copper
• D
  Mercury