Which of the following options are correct for the reaction

$2{\left[\mathrm{Au}(\mathrm{CN}{)}_2\right]}^{-}\left(\mathrm{aq}\right)+\mathrm{Zn}\left(\mathrm{s}\right)\to 2\mathrm{Au}\left(\mathrm{s}\right)+{\left[\mathrm{Zn}(\mathrm{CN}{)}_4\right]}^{2-}\left(\mathrm{aq}\right)$

A. Redox reaction
B. Displacement Reaction.
C. Decomposition reaction.
D. Combination reaction
Choose the correct answer from the options given below :