What transportation method is used to deliver propane to the storage tanks in Quadrant 4?

The correct choice, rail tankers, is the most efficient and practical method for transporting propane to storage tanks, particularly in Quadrant 4. Rail transport allows for the movement of large quantities of propane over long distances, which is essential for meeting the significant demands of storage facilities. Rail tankers are specifically designed for the safe transport of liquefied gases like propane, ensuring that the product remains secure and protected during transit.

Trucks, while also commonly used for propane delivery, may not be as efficient for large volumes or long-distance transport compared to rail. Boats and planes are generally impractical for this purpose, as boats are typically used for waterways and can have logistical limitations, while planes are more suited for smaller, urgent deliveries rather than bulk transport of propane. Therefore, rail tankers stand out as the ideal solution for transporting propane to storage tanks in this scenario.