Which of the following hydrogen bonds is the strongest?

The strength of a hydrogen bond depends on the electronegativity of the atoms involved. Fluorine is the most electronegative element in the periodic table. The $\text{H-F}$ bond is highly polar, and the interaction between the partially positive $\text{H}$ of one $\text{HF}$ molecule and the highly electronegative $\text{F}$ of another is the strongest type of hydrogen bond.