If Dev solves the puzzle, then Dev opens the treasure box. If Dev opens the treasure box, then Dev shares the sweets. It turns out that Dev does not share the sweets. Which of the following must be true?

1. A Option A: Dev opens the treasure box.
2. B Option B: Dev solves the puzzle but Dev does not open the treasure box.
3. C Option C: Dev does not solve the puzzle.
4. D Option D: Dev solves the puzzle.

Answer checked 11 October 2026 · How we write and check questions