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

Which of the following sets is in the correct order regarding the property mentioned against them?

Sets	Property
$I$. $NCCH_2COOH > FCH_2COOH > H_3CCH_2COOH$	Acidity
$II$. $CH_3CH_2CHO > PhCOCH_3 > PhCHO$	Reactivity
$III$. $H_3COCH_2CH_3 < H_3CCH_2CHO < H_3CCH_2CH_2OH$	Boiling points

The acidity of compounds $I-IV$ in water follows the order:
$I.$ ethanol
$II.$ acetic acid
$III.$ phenol
$IV.$ acetonitrile

The major product expected from the following reaction is:
$2-(\text{carbamoyl})-3-(\text{hydroxymethyl})-6-(\text{hydroxy})\text{benzoic acid} \xrightarrow{HCl_{(g)} / CCl_4} ?$

Compound $A$ was treated with a large excess of $CH_3MgBr$. The resulting product was exposed to $POCl_3$ /pyridine to give compound $B$,as one of many products.
Which of the following compounds can be $A$ ?

Which of the following compounds will undergo decarboxylation on heating?