The answer is Xingu River.
Xiaonanhai Lake is a lake in China. It begins with the letter X.
mississippi
No river in New Mexico begins with the letter X.
Lake Tana is the source of the Blue Nile and Lake Victoria of the White Nile.
It is true.
Xingu River
The Hudson River in New Yorks upstate Adirondack mountains
It is true.
The White Nile River begins at Lake No in South Sudan.
The headwaters to the Mississippi River begin at Lake Itasca in Minnesota. The terminus of the Mississippi is the Louisiana Delta region into the Gulf of Mexico.
Where a river begins is its source. It could begin at a mountain lake or as a branch of another river.
The Xi River is in China. The Xingu River is in Brazil.