The river shown on the map that indicates the farthest extent of Alexader's conquests is the Indus river.
In his thirty-two years of life, his empire extended from Greece, to the Indus Valley in the East and to Egypt in the West, where he founded the city of Alexandria . In total, his empire came to have a territorial extension of 5,200,000 km2.
I've taken the test before and the answer was six.
But as you can see the options are a)Nile, b)Danube, c)Tigris, or d)Indus
But the closest river was the Indus River.