What must you do when you are towing a caravan to help other vehicles overtake?

• A. Stop immediately and let the faster vehicle overtake
• B. Drive at least 25kph below the speed limit
• C. Keep at least 60 metres behind heavy vehicles or other vehicles towing caravans
  Explanation:

  "If you leave a gap of at least 60 metres, other vehicles overtaking you can pull in safely after overtaking you, gradually leap-frogging the line of slower vehicles. Note that this rule is only for roads without streetlights."
• D. Drive on the road shoulder