Your answer is C). In History, you'll find that most groups tend to set up civilizations around bodies of water.
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.
He did not believe they had the right to seperate, and because of that he decided to declare war against the states. There had already been tension building to this point.