Acetaldehyde and acetone can be distinguished by

In the above chemical reaction sequence,"$A$" and "$B$" respectively are:

Draw structures of the following derivatives:
$(i)$ The $2,4-$dinitrophenylhydrazone of benzaldehyde
$(ii)$ Cyclopropanone oxime
$(iii)$ Acetaldehyde dimethyl acetal
$(iv)$ The semicarbazone of cyclobutanone
$(v)$ The ethylene ketal of hexan$-3-$one
$(vi)$ The methyl hemiacetal of formaldehyde

The major product ‘$A$’ in the given reaction is:
$\text{Benzaldehyde} + \text{Acetophenone} \xrightarrow[293 \text{ K}]{OH^-} \text{'A' (Major product)}$

Oxidation of toluene with $CrO_3$ in the presence of $(CH_3CO)_2O$ gives a product '$A$' which on treatment with aqueous $NaOH$ produces

Which of the following does not reduce Fehling solution?