The correct option is (c).
Explanation
The Shiwaliks, also known as the Outer Himalayas, represent the southernmost range of the Himalayan system.
Statement 1 is Correct: The Shiwaliks extend over a width ranging from 10 to 50 km. Their altitude varies between 900 and 1100 meters. They run almost parallel to the main Himalayan ranges.
Statement 2 is Incorrect: The Shiwalik ranges are not composed of consolidated granite. Instead, they are composed of unconsolidated sediments such as gravel and alluvium brought down by rivers from the main Himalayan ranges located farther north. The core of the Great Himalayas (Himadri), not the Shiwaliks, is composed of granite.
Statement 3 is Correct: The longitudinal valleys lying between the Lesser Himalayas (Himachal) and the Shiwaliks are known as Duns. These valleys are formed due to the deposition of sediments. Prominent examples include Dehra Dun, Kotli Dun, and Patli Dun.
Key Takeaway: The Shiwaliks are the outermost Himalayan range, characterized by low altitude, unconsolidated river deposits, and the presence of longitudinal valleys called 'Duns' separating them from the Lesser Himalayas.