Why should you be cautious around a large vehicle that is backing up?

• If you are too close behind, the driver may not be able to see you in the rearview mirrors.
  Explanation:

  "You must be cautious around a large vehicle that is backing up. If you are too close behind, the driver may not see you in their rearview mirrors due to blind spots."
• If you are too far away, the driver may not be able to see you in the rearview mirrors.
• If you are too close behind, the driver will be able to see you in the rearview mirrors.
• All of the above.