Arrange the following in order of their increasing boiling point:
n-butane, n-butanol, n-butyl chloride, isobutane
1
n-butane < isobutane < n-butyl chloride < n-butanol
2
isobutane < n-butane < n-butyl chloride < n-butanol
3
n-butane < isobutane < n-butanol < n-butyl chloride
4
isobutane < n-butane < n-butanol < n-butyl chloride