Which of the following on reaction with conc. $NaOH$ gives an alcohol?

Identify the reagent $R$ used in the following reaction:
$\text{Ketone} \xrightarrow{R} \text{Semicarbazone}$

The major product $'P'$ formed in this reaction is:

In the following conversion,
$C_6H_5CN$ $\xrightarrow[(ii) H_3O^+]{(i) MeMgBr} X$ $\xrightarrow[H_3O^+]{NaOH/I_2} Y$
the major products $X$ and $Y$,respectively are

How many aldol products (excluding stereoisomers) are obtained in the given reaction?
$CH_3-CH_2-CHO + C_6H_5CHO \xrightarrow[0-5 \ ^{\circ}C]{OH^{\ominus}} ?$

When $CH_3COCH_3$ reacts with $Cl_2$ and $NaOH$,which of the following is formed?