For those listed below, which has the most polar bond? Remember the most polar bond would be attached to the greatest difference in electronegativity. Looking at the electronegativity's chart, we'd see that sulfur is 2.5, Selenium is 2.4, We'd see here 2.5, Hydrogen would be 2.1, Chlorine here would be 3.0, and here we'd have fluorine at 4.0.
Sulfur again is 2.5, and fluorine is 4.0. This would be 2.5 and this would be 3.5. Remember difference in electronegativity is the larger electronegativity value minus a smaller one. Here if we did that before -2.5 which would give us 1.5, we'd see that option D gives us the biggest difference in electronegativity which would translate into the most polar bond present.
So just remember most polar bond means biggest difference in electronegativities.