The correct answer is option 1 - Aravali. The Aravali mountain range is considered to be the oldest mountain range in India. It stretches across the states of Rajasthan, Gujarat, Haryana, and Delhi. The Aravali range has a rich geological history dating back millions of years, making it one of the oldest mountain ranges in the world. It is a result of ancient tectonic activity and has undergone several phases of erosion and uplift over time. The Aravali range is known for its scenic beauty, diverse flora and fauna, and historical significance. It is a popular tourist destination and also serves as a natural barrier protecting the surrounding regions from the harsh desert climate of Rajasthan.