The correct answer is: D. a double covalent bond
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. A double covalent bond is a covalent bond in which two pairs of electrons are shared between two atoms. This type of bond is stronger than a single covalent bond, because there are more electrons being shared.
In the oxygen molecule, each oxygen atom has six valence electrons. Two of these electrons are used to form a single covalent bond with the other oxygen atom, and the remaining four electrons are used to form a second covalent bond. This results in a double covalent bond between the two oxygen atoms.
An electrodynamic bond is a type of bond that is formed between two atoms due to the attraction of their opposite charges. This type of bond is not as strong as a covalent bond, and it is typically found in ionic compounds.
A single covalent bond is a covalent bond in which one pair of electrons is shared between two atoms. This type of bond is weaker than a double covalent bond, but it is still stronger than an electrodynamic bond.
A triple covalent bond is a covalent bond in which three pairs of electrons are shared between two atoms. This type of bond is the strongest type of covalent bond, and it is typically found in molecules with very high electronegativity differences.