List of top Chemistry Questions on carbonyl compounds asked in KCET

A hydrocarbon A (C₄H₈) on reaction with HCl gives a compound B (C₄H₉Cl) which on reaction with 1 mol of NH₃ gives compound C (C₄H₁₀N). On reacting with NaNO₂ and HCl followed by treatment with water, compound C yields an optically active compound D. The D is

The compound is