The correct statement is:
A solution of potassium hydroxide will always have more OH⁻ ions than a solution of ammonia.
Potassium hydroxide (KOH) is a strong base that fully dissociates in solution to release OH⁻ ions, resulting in a higher concentration of hydroxide ions compared to ammonia (NH₃), which is a weak base and only partially dissociates. All other statements are incorrect for this reason.