Under what conditions is it illegal to transport loose material such as dirt, sand, or gravel on public highways?

• If the bed carrying the load is not completely enclosed on both sides and on the front and rear by a tailgate, board, or panel
• If the load is not covered with a canvas or tarpaulin
• Both A & B
  Explanation:

  "No person shall transport loose material like dirt, sand, gravel, or wood chips on public highways unless the bed carrying the load is completely enclosed on all sides, front, and rear by a secure tailgate, board, or panel. The load is covered with a firmly secured canvas, tarpaulin, or other covering to prevent blowing or spilling. Agricultural products in their natural state are exempt."
• If the load is agricultural products in their natural state