The equations for two spontaneous reactions are \begin{array}{l} 3 \mathrm{Cr}(\mathrm{s})+2 \mathrm{Ga}^{3+}(\mathrm{aq}) \rightarrow 3 \mathrm{Cr}^{2+}(\mathrm{aq})+2 \mathrm{Ga}(\mathrm{s}) \\ \mathrm{Ga}(\mathrm{s})+3 \mathrm{Cu}^{2+}(\mathrm{aq}) \rightarrow 3 \mathrm{Cu}^{+}(\mathrm{aq})+\mathrm{Ga}^{3+}(\mathrm{aq}) \end{array} The strongest reductant according to these equations is

А.Cu^2 B.Ga^3+ С.Cr D.Cu+.