Final answer:
If a transport vehicle is carrying an exclusive use LSA or SCO shipment and requires RAM placarding, it must display placards on all four sides of the vehicle.
Step-by-step explanation:
The answer is D. Four. If a transport vehicle is carrying an exclusive use Limited Quantity of a hazardous material or a Small Quantity of a hazardous substance or an elevated temperature material and requires RAM (RADIOACTIVE) placarding, it must display placards on all four sides of the vehicle. This is required by the Hazardous Materials Regulations (HMR) of the U.S. Department of Transportation (DOT) to ensure proper warning and identification of the hazardous material being transported.