The reaction between an ester and an excess of Grignard reagent $(R'MgX)$ finally results in a:

The light yellow compound produced when acetone reacts with iodine and alkali is:

Which of the following,on reaction with $50\%\,KOH$,gives the corresponding alcohol and acid salt?

The compound $A$ in the following reaction is:
$A$ $\xrightarrow[(ii) Conc. H_2SO_4 / \Delta]{(i) CH_3MgBr / H_2O} B$ $\xrightarrow[(ii) Zn / H_2O]{(i) O_3} C + D$
$D \xrightarrow[Ba(OH)_2, \Delta]{} CH_3-C(CH_3)=CH-CO-CH_3$

The structure of the starting compound $P$ used in the reaction given below is:

$CH_3-CO-CH_3$ $\xrightarrow{I_2/NaOH} \underset{\text{yellow compound}}{(A)} + (B)$ $\xrightarrow{Ag - \text{powder}, \Delta} (C)$ $\xrightarrow{Dil. H_2SO_4/HgSO_4} (D)$
$A, C$ and $D$ are :-