Which of the following compounds has the most acidic hydrogen?

Which of the following reactions produce $n$-butanol?

The product $Z$ of the above reaction is:

Consider the following reaction:
Which response contains all the correct statements about this process?
$1.$ Dehydration
$2.$ $E_2$ mechanism
$3.$ Carbon skeleton migration
$4.$ Most stable alkene will form
$5.$ Single-step reaction

$A$ $\xleftarrow{CH_3OH, CH_3O^{-}}$ ($1$-methyl$-6-$oxabicyclo[$3.1$.$0$]hexane) $\xrightarrow{CH_3OH, H_2SO_4}$ $B$
$A$ $\&$ $B$ are :

Identify the reagents $X$,$Y$,and $Z$ in the following reaction schemes:
$(i)$ Benzene $\xrightarrow{X}$ Benzenesulfonic acid $\xrightarrow{Y}$ Sodium phenoxide $\xrightarrow{Z}$ Phenol
$(ii)$ Aniline $\xrightarrow{X}$ Benzenediazonium chloride $\xrightarrow{Y}$ Phenol
$(iii)$ Chlorobenzene $\xrightarrow{X}$ Sodium phenoxide $\xrightarrow{Y}$ Phenol