Correct Answer - 4
`CH_(3)-CH_(2)-CH_(2)-CH_(2)-underset(O)underset(||)(C )-CH_(3)` " " `CH_(3)-underset(CH_(3))underset(|)(CH)-CH_(2)-underset(O)underset(||)(C )-CH_(3)`
`CH_(3)-CH_(2)-underset(CH_(3))underset(|)(CH)-underset(O)underset(||)(C )-CH_(3)` " " `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C )-underset(O)underset(||)(C )-CH_(3)`