Which of the following molecules has intramolecular $H$-bonding?

In ice,the length of $H$-bonds:

Which of the following molecules are expected to exhibit intermolecular $H$-bonding?
$(I)$ Acetic acid $(II)$ $o$-nitrophenol $(III)$ $m$-nitrophenol $(IV)$ $o$-boric acid
Select the correct alternative.

Hydrogen bond energy is equal to

Which of the following hydrogen bonds is the strongest?

The hydrogen bond strength will be highest for