Identify the molecule in which central atom undergoes $$\mathrm{sp}^3$$ hybridisation?

Which one of the following conversions does NOT involve either oxidation or reduction?

Calculate $$\wedge_0$$ of $$\mathrm{CH}_2 \mathrm{ClCOOH}$$ if $$\wedge_0$$ for $$\mathrm{HCl}, \mathrm{KCl}$$ and $$\mathrm{CH}_2 \mathrm{ClCOOK}$$ are $$4.2,1.5$$ and $$1.1 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$$ respectively?

Identify the product A in the following reaction.