The structure of the isobutyl group in an organic compound is:

What is the $IUPAC$ name of the compound $CH_3-CH(C_2H_5)-CH(C_2H_5)-CH_3$?

$IUPAC$ name of the following compound is
$CH_3-CH=CH-CH_2-C\equiv CH$

Give $IUPAC$ names of the following compounds:
$(i)$ $CH_3-CH(Cl)-CH(CH_3)-CH(CH_3)-CH_2OH$
$(ii)$ $CH_3-CH(OCH_2CH_3)-CH_3$
$(iii)$ Structure of $2,6-$dimethylphenol
$(iv)$ Structure of $1-$ethoxy$-2-$nitrocyclohexane

Which of the following is the correct $IUPAC$ name of the given organic compound $(X) \ ?$

Select the structure with the correct numbering for the $IUPAC$ name of the compound.