Which of the following pairs of substances would give same gaseous product on reaction with water?

The given substances react with water in the following manner 
$$\begin{gathered} \left(\mathrm{a}\right) \mathrm{Na}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{NaOH}+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ 2{\mathrm{Na}}_2{\mathrm{O}}_2+2{\mathrm{H}}_2\mathrm{O}⟶4\mathrm{NaOH}+{\mathrm{O}}_2\left(\mathrm{g}\right) \\ \left(\mathrm{b}\right) \mathrm{Ca}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2 \\ {\mathrm{CaH}}_2+2{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ca}(\mathrm{OH}{)}_2+2{\mathrm{H}}_2 \\ (\mathrm{c}) \mathrm{CaO}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ca}(\mathrm{OH}{)}_2 \\ {\mathrm{CaC}}_2+2{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ca}(\mathrm{OH}{)}_2+{\mathrm{C}}_2{\mathrm{H}}_2 \\ (\mathrm{d}) \mathrm{Ba}+2{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ba}(\mathrm{OH}{)}_2+{\mathrm{H}}_2 \\ {\mathrm{BaO}}_2+2{\mathrm{H}}_2\mathrm{O}⟶\mathrm{Ba}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2{\mathrm{O}}_2 \end{gathered}$$
Hence, Ca and CaH₂ is the pair that gives same gaseous product on reaction with water.