Which of the following molecules has a nonpolar covalent bond?

A. H-Br

B. H-Cl

C. H-F

D. H-H

D. H-H

With the other 3, one atom is more electronegative, drawing the electrons closer to it and making one side slightly positive, making it polar. With H - H, though, both atoms are the same, so the molecules are shared evenly and it is nonpolar.