You see a stop sign ahead. What must you do?
Answer: A — Come to a complete stop
You see a stop sign ahead. This means that you must come to a complete stop as it is a requirement by law. The other options are incorrect because slowing down and driving cautiously may still result in not stopping completely, while merging into other traffic is not necessary or relevant when approaching a stop sign. Additionally, sounding your horn is not an appropriate response to a stop sign and can be considered a distraction to other drivers. Therefore, the best and necessary course of action when approaching a stop sign is to come to a complete stop.