1. **Problem Statement:** Determine which lines are perpendicular based on the given graph. 2. **Recall the rule for perpendicular lines:** Two lines are perpendicular if the product of their slopes is $-1$. 3. **Analyze the slopes:** - Lines A and B are parallel, so they have the same slope. - Line C has a different slope, not parallel to A or B. - Line D intersects all other lines and runs upward. 4. **Check perpendicularity:** - Since A and B have the same slope, neither is perpendicular to each other. - Line D intersects A and B at right angles, so D is perpendicular to A and B. - Line D is also perpendicular to C if their slopes multiply to $-1$. 5. **Conclusion:** - Lines perpendicular are D and A, and D and B. **Final answer:** Lines D and A, and lines D and B are perpendicular.