Which cannot be used to generate $H_{2}$?

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(a)$ $Li$	$(i)$ Absorbent for carbon dioxide
$(b)$ $Na$	$(ii)$ Electrochemical cells
$(c)$ $KOH$	$(iii)$ Coolant in fast breeder reactors
$(d)$ $Cs$	$(iv)$ Photoelectric cell

Choose the correct answer from the options given below:

Assertion $(A)$: $K$,$Rb$,and $Cs$ form superoxides.
Reason $(R)$: The stability of the superoxides increases from $K$ to $Cs$ due to the decrease in lattice energy.
The correct answer is:

Comment on each of the following observations:
$(a)$ The mobilities of the alkali metal ions in aqueous solution are $Li^{+} < Na^{+} < K^{+} < Rb^{+} < Cs^{+}$
$(b)$ Lithium is the only alkali metal to form a nitride directly.
$(c)$ The standard electrode potential $E^{\circ}$ for the reaction $M^{2+}_{(aq)} + 2e^{-} \to M_{(s)}$ (where $M = Ca, Sr$ or $Ba$) is nearly constant.

$Na$ and $Li$ are placed in dry air. We get

Which of the following statements is incorrect?