Consider the following reaction sequence The correct statements about $Z$ are I. It gives yellow precipitate with $\mathrm{I}_2$ and NaOH solution. II. It undergoes disproportionation reaction in the presence of concentrated NaOH solution. III. It undergoes Wolff-Kishner reduction. IV, If forms red precipitate with Fehling's reagent.

Identify $A$ and $B$ from the following reactions

$$ \text { The major product in the following transformation is } $$

Assertion (A) Ammonia and its derivatives form $\mathrm{H}_2 \mathrm{~N}-\mathrm{Z}$ undergo condensation reaction with carbonyl compounds (aldehydes and ketones).

Reason (R) This reaction is an example of irreversible reaction.

The correct option among the following is