Which of the following reagents would carry out the following transformation? ($D = $ $^2H$)

Identify the compound $A$ in the following reaction: $A + CH_3MgBr$ $\xrightarrow{\text{dry ether}} \text{intermediate}$ $\xrightarrow{H_3O^+} CH_3CH_2OH + Mg(Br)(OH)$

When cyclohexanone reacts with dimethylamine in the presence of a catalytic amount of acid,water is continuously removed during the reaction. What is the product commonly called?

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
$[A] (IV) (iii) (Q)$ $[B] (III) (iii) (P)$ $[C] (II) (iv) (R)$ $[D] (I) (i) (S)$

The reagent used in the Wolff-Kishner reduction is

Which of the following on reaction with Grignard reagent followed by hydrolysis forms a secondary alcohol?