The correct option is (a).
Explanation
The Indus River System is one of the largest river basins in the world. It originates from the glaciers of the Kailash range in Tibet near Lake Manasarovar and flows through India and Pakistan before draining into the Arabian Sea.
Statement-wise Analysis:
- Statement 1 is Correct: The total length of the Indus River is approximately 2,880 km (often rounded to 2,900 km in various geographical texts). It is considered one of the longest rivers in the world.
- Statement 2 is Incorrect: The Indus is not the shortest river in the Indian subcontinent; rather, it is one of the longest. For comparison, the Ganga is approximately 2,525 km long. The Indus covers a vast distance, although a significant portion of its course lies within Pakistan.
- Statement 3 is Incorrect: Upon entering the plains, the Indus River exhibits a very gentle slope, not a steep one. This lack of gradient causes the river to flow slowly, leading to the deposition of silt, the formation of meanders, and frequent changes in its course. A steep slope is characteristic of the river's upper course in the mountainous Himalayan region, not the plains.
Key Takeaway:
The Indus is a major antecedent river with a total length of nearly 2,900 km. While it flows rapidly through steep mountain gorges, its movement becomes sluggish with a very gentle gradient once it enters the plains.