What should you always do before passing another vehicle during the driving exam?

Answer: B — Look ahead and behind to make sure you can pass safely

Before passing another vehicle, it is important to always check your surroundings to ensure it is safe to do so. In this scenario, honking your horn (option A) is not necessary and may startle other drivers. Speeding up (option C) may also increase the risk of an accident. Passing only at intersections (option D) is not a requirement and may not always be possible. Therefore, option B, looking ahead and behind, is the safest and most responsible action to take before passing another vehicle during a driving exam. It ensures you have enough space and time to safely pass without endangering yourself or other drivers on the road.