The strongest bond among the options provided is:
B. • covalent bonds
Covalent bonds involve the sharing of electrons between atoms, which typically leads to a strong bond. Metallic bonds are also strong, particularly in metals, but covalent bonds generally have higher bond energies. Hydrogen bonds are weaker than both covalent and metallic bonds. Valence bonds is not a standard term for a type of bond but refers more to the concept in quantum chemistry dealing with the formation of covalent bonds.