The correct answer is - D. Seattle.
The ports in Los Angeles/Long Beach and Seattle are of huge economic importance to the USA. Through this two ports they are connecting with the Asian markets that are very big and productive. Through this ports there's trillions of dollars in goods that are imported into the USA and exported from the USA. The amount of trade in here is one of the largest in the world and it should be no surprise because USA is mostly trading with economic giants like China, Japan, and South Korea.
