Question Cargo inside a trailer: Answers Does not need to be secured. Should be stacked no more than three feet high. Should be secured to prevent movement. Explanation Cargo inside a trailer must be secured appropriately to prevent it from shifting in transit. This questions appears in the following tests: Alaska Class A Knowledge Test Alaska Class B Knowledge Test Arkansas Class B Knowledge Test Idaho Class A Knowledge Test Idaho Tank Louisiana Class B Knowledge Test Maine Class B Knowledge Test Michigan Class B Knowledge Test Missouri Class B Knowledge Test New Mexico Class A Knowledge Test Ohio Class A Knowledge Test Oklahoma Class B Knowledge Test South Dakota Tank Virginia Class B Knowledge Test Washington Class A Knowledge Test Wisconsin Passenger Wyoming Class A Knowledge Test