Answer:
Four covalent bonds.
Step-by-step explanation:
In a diamond, each carbon atom forms four covalent bonds with four other carbon atoms. In a diamond, each carbon shares electrons with four other carbon atoms.
Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond, they share three pairs of electrons.