Which of the following will not be reduced by $H_2$?

Which of the following pairs of reactions give $H_2$ gas as a product upon hydrolysis?

Calcium cyanamide on treatment with steam under pressure gives $NH_3$ and

Calcium imide on hydrolysis will give gas $(B)$ which on oxidation by bleaching powder gives gas $(C)$. Gas $(C)$ on reaction with magnesium gives compound $(D)$. $(D)$ on hydrolysis gives again gas $(B)$. $(B)$,$(C)$ and $(D)$ are

Which property among the following is the same for both hydrogen and deuterium molecules?

Explain the commercial production of $Dihydrogen$.