Among the hydrides formed by the group $16$ elements,only $H_2O$ has an abnormally low volatility (high boiling point). This is so because

• A
  $H_2O$ molecules are associated due to intermolecular hydrogen bonds
• B
  $H_2O$ is covalent in nature
• C
  The $O-H$ bond in $H_2O$ is very strong
• D
  The electronegativity difference of $H$ and $O$ is very large