When 1,5-dibromopentane reacts with ammonia, among several products isolated is a water- soluble compound A that rapidly gives a precipitate of AgBr with acidic AgNO₃ solution. Compound A is unchanged when treated with dilute base, but treatment of A with concentrated NaOH and heat gives a new compound B (C₁₀H₁₉N) that decolorizes Br₂ in CCl₄. Compound B is identical to the product obtained from the reaction sequence shown in Fig. P23.58.

Identify A and B and explain your reasoning.