The capital city in Mexico's high Valley of Mexico, above 2,200 metres, is Mexico City.
Mexico City stands at roughly 2,240 metres above sea level in the Basin of Mexico, a high plateau surrounded by mountains and volcanoes. Its elevation contributes to a mild highland climate, while the surrounding volcanic terrain helps explain the region's dramatic landscape.
Much of the modern city occupies the former bed of Lake Texcoco, where the Aztec capital Tenochtitlan once stood. Spanish forces captured Tenochtitlan in 1521, and Mexico City was built over and around the earlier settlement. The drained lakebed remains soft and waterlogged, making the city vulnerable to earthquakes, flooding, and gradual land subsidence.
The other options are also highland capitals, which can cause confusion: Guatemala City, San Salvador, and San José all lie at substantial elevations. However, the Valley of Mexico and the elevation above 2,200 metres specifically identify Mexico City.