Final answer:
Maritime shipping is the most cost-effective mode of transport for large, bulk products over long distances, due to its high capacity and efficiency, especially when compared to air freight, rail transport, and truck transport. Option D is correct.
Step-by-step explanation:
The cost-effective mode for shipping very large amounts of bulk products such as coal, sand, and lumber over long distances is d) Maritime shipping. Large container ships have the capacity to transport huge volumes of cargo with high efficiency, such as the typical ship traveling from Shanghai to Los Angeles, which can carry approximately 10,000 20-foot equivalent containers.
This translates to a full load of around 100,000 tons. Maritime shipping is particularly ideal for the lumber industry, where logs are first processed into boards before being transported, utilizing ships for their efficiency and capacity to move large quantities over long distances.
It is crucial to note that while other forms of transport like air freight, rail transport, and truck transport exist, they are less cost-effective than maritime shipping for bulk goods. Air freight is the least efficient due to high fuel consumption and costs, especially over large distances.
Rail and truck transport are more competitive than air, however, they are still less efficient than maritime transport when it comes to very large, heavy, or bulky shipments. Furthermore, locations with access to rail or water transport have an advantage as they provide more cost-effective transport options, reducing congestion and facilitating ease of movement for both raw materials and finished goods.