Which of the following isomers of C6H14\text{C}_6\text{H}_{14}C6H14 has the lowest boiling point?
CH3(CH2)4CH3\text{CH}_3(\text{CH}_2)_4\text{CH}_3CH3(CH2)4CH3
CH3(CH2)2CH(CH3)2\text{CH}_3(\text{CH}_2)_2\text{CH}(\text{CH}_3)_2CH3(CH2)2CH(CH3)2
CH3CH(CH3)CH(CH3)2\text{CH}_3\text{CH}(\text{CH}_3)\text{CH}(\text{CH}_3)_2CH3CH(CH3)CH(CH3)2
(CH3)3CCH2CH3(\text{CH}_3)_3\text{CCH}_2\text{CH}_3(CH3)3CCH2CH3
