The correct response is:
Potassium donates an electron to chlorine.
In the formation of potassium chloride (KCl), potassium, which is an alkali metal, donates an electron to chlorine, which is a halogen. This results in the formation of positively charged potassium ions (K⁺) and negatively charged chloride ions (Cl⁻), leading to the ionic bond in KCl.