What letter on the map indicates the the location of the yellow river?

The correct option is A
The Yellow River or Huang He, is a long river of central China that flows in directions NE, E, S and again, NE, through the provinces of Qinghai, Gansu, Henan, Shandong, Shanxi and Shaanxi, and autonomous regions from Inner Mongolia and Ningxia, until draining in the Bohai Sea. It has a length of 5464 km, which makes it the sixth longest river in the world, behind the Amazon, Nile, Yangtze, Mississippi-Missouri and Yeniséi-Angará.