Why can it be dangerous to overtake even on clearly visible, straight roads?

Your answer is correct because overtaking on straight, clearly visible roads can still be dangerous for two main reasons. First, oncoming traffic may be traveling faster than you initially expect, reducing the time and space available to overtake safely. Second, the distance needed to complete the overtaking maneuver might be longer than you first estimated, especially if your vehicle accelerates slower or the road is longer than it appears. These factors mean that even when the road looks clear, you must carefully assess speed and distance before overtaking to avoid collisions.