The correct answer is B. A large naval blockade.
The Union used a large expansive naval blockade to stop most of the South's cotton trade making it difficult for trading ships to come or go since the South managed the greater part of its exchange (trade) through water ports. The blockade was a push to cut off provisions or correspondences from a specific territory. When the Union blocked the route with a large naval blockade, the cotton distributors from the South were forced to take longer routes to achieve its destination and this way theSouth cotton distributors could not fulfill the customer's orders.
