An organic compound $A$ reacts with methyl magnesium iodide to form an addition product,which on hydrolysis gives compound $B$. Compound $B$ gives a blue color in the Victor Meyer test. What are compounds $A$ and $B$ respectively?

Which of the following compounds gives only a primary alcohol on reaction with a Grignard reagent $(RMgX)$?

Identify the product $P$ from the following sequence of reactions?

Columns $1$,$2$,and $3$ contain starting materials,reaction conditions,and type of reactions,respectively.

$Column-1$	$Column-2$	$Column-3$
$(I)$ Toluene	$(i)$ $NaOH / Br_2$	$(P)$ Condensation
$(II)$ Acetophenone	$(ii)$ $Br_2 / h\nu$	$(Q)$ Carboxylation
$(III)$ Benzaldehyde	$(iii)$ $(CH_3CO)_2O / CH_3COOK$	$(R)$ Substitution
$(IV)$ Phenol	$(iv)$ $NaOH / CO_2$	$(S)$ Haloform

$(1)$ For the synthesis of benzoic acid,the only $CORRECT$ combination is
$[A] (III) (iv) (R)$ $[B] (IV) (ii) (P)$ $[C] (I) (iv) (Q)$ $[D] (II) (i) (S)$
$(2)$ The only $CORRECT$ combination in which the reaction proceeds through radical mechanism is
$[A] (I) (ii) (R)$ $[B] (II) (iii) (R)$ $[C] (III) (ii) (P)$ $[D] (IV) (i) (Q)$
$(3)$ The only $CORRECT$ combination that gives two different carboxylic acids is
$[A] (IV) (iii) (Q)$ $[B] (III) (iii) (P)$ $[C] (II) (iv) (R)$ $[D] (I) (i) (S)$

Which of the following reactions are incorrect?
$(a)$ $CH_2(COOH)_2 \xrightarrow{\Delta} CH_3COOH + CO_2$
$(b)$ Aniline $\xrightarrow{CH_3Cl/AlCl_3}$ $p$-chloroaniline
$(c)$ Phenol $\xrightarrow{CHCl_3 + aq. NaOH}$ Salicylic acid
$(d)$ $CH_3CHO + NaHSO_3 \rightleftharpoons CH_3CH(OH)SO_3Na$
$(e)$ Benzene $\xrightarrow{CO, HCl, Anhydrous AlCl_3/CuCl}$ Benzaldehyde

Among the following compounds,which will give maximum enol content in solution?