What is the maximum number of hydrogen bonds in which a single water molecule can participate?

The correct order of strength of hydrogen bonding in the following compounds is:

Use the information and data given below to answer the questions $(a)$ to $(c)$. Stronger intermolecular forces result in higher boiling point.
Strength of London forces increases with the number of electrons in the molecule.
Boiling points of $HF, HCl, HBr$ and $HI$ are $293 \ K, 189 \ K, 200 \ K$ and $238 \ K$ respectively.
$(a)$ Which type of intermolecular forces are present in the molecules $HF, HCl, HBr$ and $HI$?
$(b)$ Looking at the trend of boiling points of $HCl, HBr$ and $HI$,explain out of dipole-dipole interaction and London interaction,which one is predominant here.
$(c)$ Why is the boiling point of hydrogen fluoride highest while that of hydrogen chloride lowest?

Among $H_2O, H_2S, H_2Se$ and $H_2Te$,the substance with the highest boiling point is,

The molecular interactions responsible for hydrogen bonding in $HF$ are:

Hydrogen bonding is $NOT$ responsible for: