What does a solid white line on the road indicate?

Answer: C — Do not change lanes

A solid white line on the road serves as a clear indication that lane changes are discouraged and should not be made. This marking is meant to help maintain traffic flow and ensure the safety of road users by keeping vehicles in their designated lanes. When you see a solid white line, it often signifies that crossing it could pose a risk to you or others on the road, thus promoting caution. Understanding this distinction is crucial for safe driving practices, as it emphasizes the importance of adhering to lane markings to prevent collisions and ensure a smooth driving experience. In contrast, certain other markings, such as dashed lines, indicate where passing or changing lanes is permissible.