Which of the following undergoes decarboxylation most readily on being heated?

Number of equivalents of Grignard reagent $(x)$ used in the reaction is

Match List-$I$ with List-$II$.

List-$I$ (Name of reaction)	List-$II$ (Reagent used)
$A$. Hell-Volhard-Zelinsky reaction	$I$. $NaOH + I_2$
$B$. Iodoform reaction	$II$. $(i) CrO_2Cl_2, CS_2; (ii) H_2O$
$C$. Etard reaction	$III$. $(i) Br_2 / \text{red phosphorus}; (ii) H_2O$
$D$. Gatterman-Koch reaction	$IV$. $CO, HCl, \text{anhyd. } AlCl_3$

Choose the correct answer from the options given below:

The increasing order of the acidity of the following carboxylic acids is:

Ethanol on reaction with acetic anhydride gives

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.