The heights of these mountain peaks from sea level are:
- Nanda Devi (C): 7,816 meters
- Nanga Parbat (D): 8,126 meters
- Kanchenjunga (A): 8,586 meters (3rd highest peak in the world)
- K-2 (B): 8,611 meters (2nd highest peak in the world)
Hence, Option 1: (C), (D), (A), (B) represents the correct increasing order of heights, with Nanda Devi being the shortest at 7,816m and K-2 being the tallest at 8,611m among these peaks. Correct