Urotropine is

The major product of the following reaction sequence is

Arrange the following compounds in the increasing order of their equilibrium constants for the formation of a hydrate:
$(I)$ $6$-amino-$1$-tetralone
$(II)$ $7$-amino-$1$-tetralone
$(III)$ $1$-tetralone
$(IV)$ $6$-nitro-$1$-tetralone

The products $(A)$ and $(B)$ respectively in the above Beckmann rearrangement reactions are:

Which of the following compounds does not undergo haloform reaction?

In the following reactions,
$CH_3COCH_3 \xrightarrow[(ii) D_3O^+]{(i) NaBH_4} X$
$CH_3COCH_3 \xrightarrow[(ii) H_3O^+]{(i) NaBD_4} Y$
$X$ and $Y$ are