Final answer:
H₂ has nonpolar covalent bonds because both hydrogen atoms share the same electronegativity, leading to an equal sharing of electrons and hence a nonpolar bond.
Step-by-step explanation:
The substance that has nonpolar covalent bonds among the options given is (d) H₂. In a nonpolar covalent bond, the electronegativity difference between the bonded atoms is minimal, allowing the electrons to be shared more or less equally. This is true for the H-H bond in H₂ as both hydrogen atoms have the same electronegativity value of 2.1, making the difference zero and the bond nonpolar. Other substances listed, such as NaBr, CO, and NO₂, do not have nonpolar covalent bonds; NaBr is ionic, while CO and NO₂ have polar covalent bonds due to differences in electronegativity.