The IUPAC name of the given compound

The correct answer is Option (2) → 3-Methylbutoxybenzene

An alkyl aryl ether is named in the IUPAC system as an alkoxybenzene: benzene is the parent and the O–alkyl group is the alkoxy substituent (e.g. \( \ce{C6H5OCH3} \) is methoxybenzene). The alkoxy chain is numbered from the carbon attached to oxygen.

Here the group on oxygen is –\( \ce{CH2-CH2-CH(CH3)-CH3} \): a four-carbon (butoxy) chain with a methyl group on its third carbon:

    \( \ce{C6H5-O-}\overset{1}{\ce{CH2}}{-}\overset{2}{\ce{CH2}}{-}\overset{3}{\ce{CH}}(\ce{CH3}){-}\overset{4}{\ce{CH3}} \)

So the name is 3-methylbutoxybenzene.