Operating a truck, road tractor, or truck tractor while another person occupies a trailer or semi-trailer being towed is a class B misdemeanor. However, it is not an offense if:

• The trailer or semi-trailer was empty.
• The person towing did not know someone was in the trailer.
• The person in the trailer was in a part designed for human habitation.
• Both B & C.
  Explanation:

  "Operating a truck, road tractor, or truck tractor when another person occupies a trailer or semi-trailer being drawn by the vehicle is a class B misdemeanor. However, it is a defense to prosecution that the person: 1. Towing the vehicle did not know another person occupied the trailer or semi-trailer. 2. Occupying the trailer or semi-trailer was in a part of the vehicle designed for human habitation."