Alcoholic fermentation is brought about by the action of

In the following sequence of reactions,the compound $D$ is
$CH_3CH_2OH$ $\xrightarrow{P + I_2} A$ $\xrightarrow[{ether}]{Mg} B$ $\xrightarrow{HCHO} C$ $\xrightarrow{H_2O} D$

Which of the following alcohols is $NOT$ prepared by acid catalyzed hydration of alkenes?

Among the following,the appropriate reactants for the preparation of $1$-ethyl cyclohexanol are:

$CH_3-CH_2-C(Ph)(OH)-CH_3$ can not be prepared by:

In the given reaction,identify $R$ in $RMgBr$:
$CH_3CH_2CHO \xrightarrow[2. H_3O^+]{1. RMgBr} CH_3CH_2CH(OH)CH_2CH_3$