The river Ganga rises from

Major Himalayan rivers of North India originate as meltwater from high-altitude glaciers and snowfields; that meltwater collects into small streams which combine downstream to form the main river.

The Ganga's headstream, the Bhagirathi, emerges from Gaumukh, the snout (terminus) of the Gangotri Glacier in the Uttarakhand Himalayas. The Bhagirathi meets the Alaknanda at Devprayag, and the river is called the Ganga from that confluence onward. So the Gangotri glacier correctly identifies the river's glacial source among the given options.

• Aravalli range: a low, geologically ancient hill system with no glaciers or perennial snowfields, so it cannot be the source of a Himalayan river.

• Ladakh glacier: glaciers in the Ladakh region lie in the Indus river basin and feed the Indus system, not the Ganga.

• Milam glacier: it feeds the Gori Ganga, a tributary that joins the Kali (Sharda) and then the Ghaghara before merging with the Ganga far downstream -- a different tributary chain from the Bhagirathi headstream that forms the river at Devprayag.

Hence, the river Ganga rises from the Gangotri glacier.