The $IUPAC$ name of the compound $CH_3-CH(CH_3)-CH_2-CH(OH)-CH_3$ is .........

The $IUPAC$ name(s) of the following compound is(are):
$[A]$ $4-$methylchlorobenzene
$[B]$ $4-$chlorotoluene
$[C]$ $1-$chloro$-4-$methylbenzene
$[D]$ $1-$methyl$-4-$chlorobenzene

Give the structures of the following:
$(a)$ $n$-propyl $(b)$ Isopropyl $(c)$ Isobutyl $(d)$ Isopentyl
What is common in all $Iso$ groups?

The $IUPAC$ name of the given compound is:

Provide the $IUPAC$ name for the following compound:
$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,H\,\,\,\,\,{C_4}{H_9}} \\
{\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{CH_3CH_2 - C - C - CH_3} \\
{\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,CH_3\,\,\,\,CH_3}
\end{array}$

The $IUPAC$ name of the given compound is: