(I) `CH_(3)-CH_(2)-CH_(2)-CH_(2)-OH`
(II) `CH_(3)-CH_(2)-underset(underset(OH)(|))(C H)-CH_(3)`
(III) `CH_(3)- underset(underset(OH)(|))overset(overset(CH_(3))(|))(C )-CH_(3)`
(IV) `CH_(3)- underset(underset(CH_(3))(|))(C H)-CH_(2)-OH`
(V ) `CH_(3)-CH_(2)-O-CH_(2)-CH_(3)` (VI) `CH_(3)-O-CH_(2)-CH_(2)-CH_(3)` (VII) `CH_(3)-O- underset(underset(CH_(3))(|))(C H)-CH_(3)`
Identify the pairs of compounds that represents chain isomerism

Explanation

The possess same group but different carbon chain.
(I) `underset("Butan-1-ol")(CH_(3)-CH_(2)-CH_(2)-CH_(2)-OH)`
(II) `underset("2-methyl prop-2-ol")(CH_(3)-underset(underset(OH)(|))overset(overset(CH_(3))(|))(C )-CH_(3))`
(II) `underset("Butan-2-ol")(CH_(3)-CH_(2)-underset(underset(OH)(|))(C H)-CH_(3))`
(IV) `underset("2-methyl-propan-1-ol")(CH_(3)-underset(underset(CH_(3))(|))(CH)-CH_(2)-OH)`