The hydrogen bonded to the most electronegative element will have the greatest partial positive charge. This is because electronegativity corresponds to the ability of the nucleus of an atom to attract the electrons involved in a chemical bond.
So the more electronegative, the more partial negative charge the atom will have.
Linus Pauling created a scale of the most electronegative elements, which can be of help in determining the intensity of polarization of different bonds:
F > O > N > C > Br > I > S > C > P > H
In this case, F is the most electronegative element.
So hydrogen will have the greatest partial positive charge bonded to F.
Answer: HF