Answer: Ganga
Notes: The Ganga or Ganges is the longest river of India flowing over 2,510 kms of mountains, valleys and plains, and is the second greatest river in the world by water discharge. It originates in the snowfields of the Gangotri Glacier in the Himalayas as the Bhagirathi River. It is considered the holiest of rivers by Hindus. It was declared a national river by Prime Minister Manmohan Singh in 2008 in order to achieve the objectives of the Ganga Action Plan, initiated by PM Rajiv Gandhi in 1985.
