$$K_a$$ values for acids $$\mathrm{H}_2 \mathrm{SO}_3, \mathrm{HNO}_2, \mathrm{CH}_3 \mathrm{COOH}$$ and $$\mathrm{HCN}$$ are respectively $$13 \times 10^{-2}, 4 \times 10^{-4}, 1.8 \times 10^{-5}$$ and $$4 \times 10^{-10}$$, which of the above acids produces stronger conjugate base in aqueous solution?
$$A, B$$ and $$C$$ respectively are
The reagent which can do the conversion $$\mathrm{CH}_3 \mathrm{COOH} \longrightarrow \mathrm{CH}_3-\mathrm{CH}_2-\mathrm{OH}$$ is
$$\begin{aligned} & \mathrm{CH}_3 \mathrm{CHO} \xrightarrow[\text { (ii) } \mathrm{H}_3 \mathrm{O}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{MgBr}} A \xrightarrow[\Delta]{\text { Conc. } \mathrm{H}_2 \mathrm{SO}_4} \\ & B \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O}, \mathrm{OH}^{-}]{\text {(i) } \mathrm{B}_2 \mathrm{H}_6} C \\ & \end{aligned}$$
$$A$$ and $$C$$ are