Of the Compounds Shown Below, the One Numbered _____ Has

Short Answer

Of the compounds shown below, the one numbered _____ has the highest boiling point. $\begin{array}{cccc}\mathrm{O} & \mathrm{OH} & \mathrm{CH}_{3}\\||&|&|\\\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CCH}_{3}&\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHCH}_{3}&\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHCH}_{3}\\1.&2.&3.\end{array}$