Pick the odd one out regarding the properties of sodium borohydride $(NaBH_4)$.

What do you expect the nature of hydrides is,if formed by elements of atomic numbers $15$,$19$,$23$,and $44$ with dihydrogen? Compare their behaviour towards water.

The calorific value of producer gas is low because of:

In the following reaction,assign the state for the underlined atom in the product of complete hydrolysis at $R.T.$:
$\underline{B}_2H_6 + H_2O \longrightarrow H_3BO_3 + H_2 \uparrow$

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

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Isotopes of hydrogen have almost same chemical properties,but difference in their rates of reaction.
Reason $R:$ Isotopes of hydrogen have different enthalpy of bond dissociation.
In the light of the above statements,choose the most appropriate answer from the options given below: