Which among the following isomers of $C_4H_9OH$ has the lowest boiling point?

Identify $A$ in the given reaction.

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Butan$-1-$ol has higher boiling point than ethoxyethane.
Reason $R:$ 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:

An alcohol $X$ $(C_5H_{12}O)$ when reacted with conc. $HCl$ and anhydrous $ZnCl_2$ produces turbidity instantly. The alcohol $X$ can be prepared from which of the following reactions?

An organic compound $X$ on treatment with $PCC$ in dichloromethane gives the compound $Y$. Compound $Y$ reacts with $I_{2}$ and alkali to form a yellow precipitate of triiodomethane. The compound $X$ is

The final product $(III)$ is