The compound that results from the formation of an ionic bond is:
C. NaCl
Sodium chloride (NaCl) is formed when sodium (Na) donates an electron to chlorine (Cl), resulting in the formation of a positively charged sodium ion (Na⁺) and a negatively charged chloride ion (Cl⁻), which are held together by electrostatic forces in an ionic bond. The other compounds (H2O, NO2, CO2) involve covalent bonding.