What will be the product $B$ in the following sequence of reactions?
$HC \equiv CH$ $\xrightarrow{30\% \, H_2SO_4, \, HgSO_4} A$ $\xrightarrow{NaOH} B$

An organic compound $A$ has the molecular formula $C_3H_6O$ and it undergoes the iodoform test. When saturated with dilute $HCl$,it gives $B$ with the molecular formula $C_9H_{14}O$. $A$ and $B$ respectively are:

Fehling's test is positive for

$A$ tertiary alcohol $H$ upon acid-catalysed dehydration gives a product $I$. Ozonolysis of $I$ leads to compounds $J$ and $K$. Compound $J$ upon reaction with $KOH$ gives benzyl alcohol and a compound $L$,whereas $K$ on reaction with $KOH$ gives only $M$.
$1.$ Compound $H$ is formed by the reaction of
$2.$ The structure of compound $I$ is
$3.$ The structures of compounds $J, K$ and $L$,respectively,are
$(A)$ $PhCOCH_3, PhCH_2 COCH_3$ and $PhCH_2 COO^{-} K^{+}$
$(B)$ $PhCHO, PhCH_2 CHO$ and $PhCOO^{-} K^{+}$
$(C)$ $PhCOCH_3, PhCH_2 CHO$ and $CH_3 COO^{-} K^{+}$
$(D)$ $PhCHO, PhCOCH_3$ and $PhCOO^{-} K^{+}$
Give the answer for questions $1, 2$ and $3.$

In the following sequence of reactions,the final product $D$ is:

The reaction between benzaldehyde and acetophenone in the presence of dilute $NaOH$ is known as: