$CuSO_4$ solution is not stable in $Zn$ container because of

Question

$\begin{array}{1 1}(a)\;\text{because of formation of}(Cu)_25O_4\\(b)\;\text{because of formation of Cu}\\(c)\;\text{because of formation Cu-Zn alloy}\\(d)\;\text{because of formation of }Zn5O_3\end{array}$