El Salvador is located on the coast of the Pacific Ocean, which means that likely the goods are arriving by ships, since the sea route is preferred due to its relatively low cost - especially for non-perishable goods.
Additionally, it is located not far from the Panama Canal - which increases its trade possibilities to also include the Atlantic Ocean ports.
The answer is D. The Pacific is West of Latin America while the Atlantic and the Caribbean are East of it. The Mediterranean is located in the Middle East (where Egypt and Italy are located).
C. In the mountians of Colorado