What are $X$ and $Y$ respectively in the following reactions?

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

Identify the final product in the following reaction:
$CH_3-CH(OH)-COOH \xrightarrow{\Delta} \text{Product}$

The reaction sequence$(s)$ that would lead to $o$-xylene as the major product is (are)

In the following reactions,$P$,$Q$,$R$,and $S$ are the major products.
The correct statement$(s)$ about $P$,$Q$,$R$,and $S$ is (are)
$(A)$ $P$ and $Q$ are monomers of polymers dacron and glyptal,respectively.
$(B)$ $P$,$Q$,and $R$ are dicarboxylic acids.
$(C)$ Compounds $Q$ and $R$ are the same.
$(D)$ $R$ does not undergo aldol condensation and $S$ does not undergo Cannizzaro reaction.

Ester and acetamide are distinguished by