Answer:
C) hydrogen bonds
Step-by-step explanation:
The abnormally high boiling point of HF compared to HCl is primarily due to the intermolecular forces called hydrogen bonds.
Hydrogen bonds are intermolecular forces of attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom (oxygen, nitrogen or fluorine).
Hydrogen bonds are very strong force of attraction compared to dipole - dipole attraction that holds the HCl together.