1. **State the problem:** We have four pictures (bell, book, apple, cat) arranged in a row as a code. The clues are: - The bell is next to the book. - The apple is somewhere between the bell and the cat. - The book is somewhere to the right of the cat. We want to find which question (A, B, C, or D) will allow us to deduce the exact order of the four pictures. 2. **Analyze the clues:** - "Bell is next to book" means bell and book are adjacent. - "Apple is between bell and cat" means in the sequence, apple lies somewhere strictly between bell and cat. - "Book is to the right of cat" means cat appears before book in the sequence. 3. **Possible orders given clues:** Let's denote positions 1 to 4 from left to right. - Since book is to the right of cat, cat must be before book. - Bell and book are adjacent. - Apple is between bell and cat. 4. **Check each question's effect:** - A: "Is the apple next to the book?" Knowing this adjacency helps but may not fix the entire order. - B: "Is the cat next to the apple?" This adjacency could clarify the relative positions of cat and apple. - C: "Is the bell next to the cat?" Since bell must be next to book, and book is right of cat, this question can clarify bell-cat adjacency. - D: "Is the book next to the cat?" Since book is right of cat, this question clarifies if they are adjacent. 5. **Which question allows deducing the code?** Only question D directly tests adjacency between book and cat, which combined with the clues can fix the order uniquely. **Final answer:** Question D allows deducing the code. **Summary:** The question "Is the book next to the cat?" (D) will allow you to deduce the code uniquely given the clues.