Which amusement park is located in Arlington, Texas?

Six Flags Over Texas is the correct answer because it is a well-known amusement park located in Arlington, Texas. Opened in 1961, it was the first of the Six Flags chain of theme parks, offering a wide variety of attractions including roller coasters, family rides, and entertainment options. The park has become a significant part of Arlington's identity and draws visitors from around the region and beyond.

In contrast, Magic Kingdom is located at Walt Disney World in Florida, SeaWorld Texas is situated in San Antonio, and Legoland Discovery Center is found in Grapevine, which is nearby but not in Arlington itself. Each of these options represents distinct entertainment experiences but does not pertain to the location sought in the question about Arlington, Texas.