Final answer:
When passing, it is important to check your vehicle's blind spots to ensure safe lane changes and prevent accidents.
Step-by-step explanation:
Always check the blind spots when passing because someone might drive out of it. The correct answer to this question is A) Blind spots. Blind spots are areas around your vehicle that are not visible in your rearview or side mirrors. It's essential for safe driving to physically turn your head and check these areas to ensure no other vehicles are in close proximity before you change lanes or pass another car. This practice helps in preventing potential collisions on the road.