Which of the following mountains have the oldest rocks in India?
Explanation: The Aravalli Range is the oldest fold mountains in India. The northern end of the range continues as isolated hills and rocky ridges into Haryana state, ending in Delhi. The famous Delhi Ridge is the last leg of the Aravalli Range, which traverses through South Delhi and terminates into Central Delhi where Raisina hill is its last extension. It is one of the worlds' oldest mountain ranges.