Carbon is least likely to be part of an ionic bond.
Explanation:
Ionic bond is formed by the process of transformation of electron between two atoms.
In ionic bonds the charges of cations and anions are balanced.
For the atom of carbon to form an ionic bond it must transfer 4 electron or gain 4 electron from another atom, this is not likely to occur in the chemical reaction.
Hence carbon atom shares 4 electron so that it can have the configuration of noble gas.