Which one of the following reactions can be used for the preparation of $\beta$-hydroxy acid derivatives?

In the reaction,$C_6H_5COCH_3 \xrightarrow[Zn-Hg / \text{conc. } HCl]{[H]} X$,$X$ is

Compound $(A)$ with molecular formula $C_{11}H_8O$ does not undergo self-aldol condensation. Upon ozonolysis,it yields $Ph-CHO$ and $2B$,where $B$ on oxidation with $Ag^{+}$ gives oxalic acid. Identify compound $(A)$.

The reaction sequence is as follows:
$HOOC-CH_2-CH_2-CH_2-CH_2-COOH$ $\xrightarrow[BaCO_3]{\Delta} A$ $\xrightarrow{NH_2-NH_2} B$ $\xrightarrow[KOH]{\text{heat}} C$
The final product $(C)$ obtained is:

The reaction shown below is called:
$CH_3-CHO + 4[H] \xrightarrow{Zn-Hg / \text{conc. } HCl} CH_3-CH_3 + H_2O$

Primary aldehyde on oxidation gives