When you are entering the road from a private road or driveway, you must yield to...?

Answer: C — Pedestrians on the sidewalk and vehicles on the road

When entering the road from a private road or driveway, it is important to remember that pedestrians on the sidewalk have the right of way. Therefore, option A and option B are incorrect as they only mention one type of traffic that you must yield to. Option D is also incorrect because even if the road appears clear, there may still be pedestrians on the sidewalk that you need to yield to. Therefore, the correct answer is option C as it includes both pedestrians on the sidewalk and vehicles on the road. Remember to always be cautious and yield to all forms of traffic when entering a road from a private road or driveway.