The boiling points of alcohols decrease as the alkyl chain branching increases.

Give the reasons :

Boiling points of alcohols are higher than ethers.

Given below are two statements : One is labelled as $\mathrm{Assertion} \mathrm{A}$ and the other is labelled as $\mathrm{Reason} \mathrm{R}$.

$\mathrm{Assertion} \mathrm{A} :$ Butan–$1$–ol has higher boiling point than ethoxyethane.

$\mathrm{Reason} \mathrm{R} :$ Extensive hydrogen bonding leads to stronger association of molecules.

In the light of the above statements, choose the correct answer from the options given below :

Arrange the following alcohols in order of their increasing boiling points.

Pentan-$1$-ol                     Butan-$2$-ol         Butan-$1$ol             Propane-$1$-ol                Ethanol

       I                                       II                        III                           IV                                 V