How Good Is Your Geographic? [5]

[Starter]

The correct answer is

1.Amazon
2.Congo
3.Ganges-Brahmaputra
4.Orinoco

I DON'T KNOW WHO WINS!

..so somebody pose a Q.

Anfield5 got three of the four, so it goes to him.

I would have bet, between my two, that it was the Rio Negro. I remembered that one of the largest rivers in the world was a tributary of the Amazon, but couldn't remember the name until this morning. The Ganges was just covering my bet .