Read this: The Houston–The Woodlands–Sugar Land MSA's gross domestic product (GDP) in 2012 was $489 billion, making it the fourth-largest of any metropolitan area in the United States and larger than Austria's, Venezuela's, or South Africa's GDP. Only 26 countries other than the United States have a gross domestic product exceeding Houston's regional gross area product (GAP). In 2010, mining (which consists almost entirely of exploration and production of oil and gas in Houston) accounted for 26.3% of Houston's GAP up sharply in response to high energy prices and a decreased worldwide surplus of oil production capacity, followed by engineering services, health services, and manufacturing.

Where in the rankings does Texas's gross domestic product place it compared to other U.S. domestic areas?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable