Final answer:
The true statement about backing a heavy vehicle is to avoid it when possible. Helpers should be visible and use clear communication signals, and it's generally safer to back toward the driver's side for better visibility.
Step-by-step explanation:
The correct statement about backing a heavy vehicle is 'Avoid backing whenever you can'. When you must back up, it's important to use every precaution to prevent accidents. Using helpers can be crucial, and they should remain visible to the driver and preferably utilize hand signals in addition to spoken signals to ensure clear communication. Lastly, when backing a heavy vehicle it's usually safer to back toward the driver's side (left side in countries where drivers sit on the left side of the vehicle) of the vehicle because this allows the driver a better view of the path of the vehicle.