The equation which is balanced and represents the correct product(s) is :

Question

$(a)\;LiO_{2} +2KCl \to 2LiCl +K_{2}O\qquad(b)\; [CoCl(NH_{3})_{5}]^{+}+5H^{+} \to Co^{2+} +5NH_{4}^{+}+Cl^{-}\qquad(c)\;[Mg(H_{2}O)_{6}]^{2+} + EDTA^{4-} \underrightarrow{excess\;NaOH}\;[Mg(EDTA)]^{2+} +6H_{2}O\qquad(d)\;CuSO_{4} +4 KCN \; \to \; K_{2} [Cu(CN)_{4}] +K_{2}SO_{4}$