There are three boxes: one contains only apples, one contains only oranges, and one contains both apples and oranges. Each box is labeled incorrectly. You can pick one fruit from one box. Which box should you choose to correctly label all boxes?

Answer: C. The box labeled both
Choosing from the box labeled 'both' (which is incorrect) will reveal either an apple or an orange, allowing you to correctly deduce the contents of all boxes.