The potential energy of an object, such as a child, is highest at the point of greatest height relative to a reference level. In many scenarios, this typically means when the child is at the highest position, such as at the top of a slide or swing.
If you're looking for a specific answer based on the numbered options you've provided (1, 2, 3, 4), then the option that corresponds to the highest point of elevation would be the best choice. Depending on the context that's not provided here, select the number that represents the highest position.
If you can provide more context or details related to these points, I could help clarify further!