Which of the following has highly acidic hydrogen?

Provide identification tests for the following pairs of compounds:
$(1)$ Phenol and carboxylic acid
$(2)$ Formic acid and acetic acid
$(3)$ Acetic acid and ethanol
$(4)$ Acetic acid and acetone
$(5)$ Aldehyde and ketone
$(6)$ Acetaldehyde and acetone
$(7)$ Acetaldehyde and formaldehyde
$(8)$ Benzaldehyde and acetaldehyde

The product $(C)$ of the above reaction is:

$CH_3COOH \xrightarrow{LiAlH_4} A$
$A + CH_3COOH \xrightarrow{H_3O^+} B + H_2O$
In the above reactions,'$A$' and '$B$' respectively are:

How will you bring about the following conversions in not more than two steps?
$(i)$ Propanone to Propene
$(ii)$ Benzoic acid to Benzaldehyde
$(iii)$ Ethanol to $3-$Hydroxybutanal
$(iv)$ Benzene to $m-$Nitroacetophenone
$(v)$ Benzaldehyde to Benzophenone
$(vi)$ Bromobenzene to $1-$Phenylethanol
$(vii)$ Benzaldehyde to $3-$Phenylpropan$-1-$ol
$(viii)$ Benzaldehyde to $\alpha-$Hydroxyphenylacetic acid
$(ix)$ Benzoic acid to $m-$Nitrobenzyl alcohol

Which of the following compounds on hydrolysis gives reactant $(A)$?