After Mexico, Canada, and the United States signed the North American Free Trade Agreement (NAFTA), trade among these three countries A. increased significantly. B. became less competitive. C. remained unaffected. D. dropped to a record low.
I'm not so great on history.....
Try reading this article: https://www.inc.com/encyclopedia/north-american-free-trade-agreement-nafta.html
I think it is B too maybe. If you get it wrong don't blame me!!!