The correct answer is Tigris and Euphrates
The Tigris River is located in the eastern portion of the region that the ancient Greeks called Mesopotamia, a plateau of volcanic origin located in the Middle East, in the current territory of Iraq and adjacent lands.
In effect, "Mesopotamia" means "land between rivers", since it is located between the valleys of the Tigris and Euphrates rivers.
The Euphrates River, along with the Tigris River, delimits the region known as Mesopotamia, where some of the first civilizations of mankind lived.
The first archaeological references (of Sumerian origin) in this region, date from the third millennium BC and, without surprise, this was the cradle of cities like Ur, Ereque, Quis and, the best known of all, Babylon, which extended through the flooded plains full of ponds and lakes and was inhabited on both sides of the river.