Answer:
D. the United States
Step-by-step explanation:
Until the year of 2006, the largest importer of oil in the world was the United States. In fact, the United States were the leader in oil imports for almost a century. In the mid 2000's though, this started to change, with the United States starting to import less and less oil, while increasing their own production, as well as using alternative energy sources. China, on the other hand, was constantly consuming more and more, and since it lacks it as natural resources, it was imported, so China propelled to the top as the biggest importer of oil in the world.