Which of the following pairs of compounds can be differentiated by $NaHCO_3$ as well as by $NaOH$?

The final product $[D]$ of the reaction is
$CHCl_3$ $\xrightarrow[hv]{O_2} [A]$ $\xrightarrow{EtOH} [B]$ $\xrightarrow{2 \ mole \ MeMgBr} [C]$ $\xrightarrow{CaOCl_2} [D]$ $\xrightarrow{\Delta} CH_3-C(=O)-CH_3$

What are $\underline{A}, \underline{B}, \underline{C}$ in the following reactions?
$(I)$ $(CH_3 CO_2)_2 Ca \stackrel{\Delta}{\longrightarrow} \underline{A}$
$(II)$ $CH_3 CO_2 H \underset{\text{Red P}}{\stackrel{HI}{\longrightarrow}} \underline{B}$
$(III)$ $2 CH_3 CO_2 H \stackrel{P_4 O_{10}}{\longrightarrow} \underline{C}$
$\underline{A} \quad \underline{B} \quad \underline{C}$

Hydrolysis of an ester gives a carboxylic acid which on Kolbe's electrolysis yields ethane. The ester is

Find out the major products $A$ and $B$ from the following reaction sequence.

Which is the major product of the following reaction?