Which mountain range separates the Brahmaputra Valley from the Barak Valley in Assam?

Which mountain range separates the Kullu Valley from the Spiti Valley in Himachal Pradesh?

Which of the following is the oldest mountain range in India?

Which one of the following mountain ranges is spread over only one state in India?

In which of the following states are the Aravalli Ranges located?

The oldest mountain range in India is