The element that is likely to form a ionic bond with potassium is Cl (answer A)
Step-by-step explanation
Ionic bond - is a bond formed when a metal and a non metal react.
Metal loses electron ( donate electrons) while non metal gains electrons ( accept electrons) to form ionic bond.
potassium is a metal while Chlorine(Cl) is a non metal. They react to form an ionic bond by potassium donating 1 electron while chlorine accept 1 electron.