In which of the following, intramolecular hydrogen bonding is present?

The major product in Reimer-Tiemann reaction is $X$. The reactants are $Y$ and $Z, X, Y$ and $Z$ are respectively

The increasing order of boiling points of the following is

$$ \begin{array}{cccc} \mathrm{CH}_3-\mathrm{O}-\mathrm{CH}_3 & \mathrm{CH}_3 \mathrm{CHO} & \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_3 & \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH} \\ \text { I } & \text { II } & \text { III } & \text { IV } \end{array} $$