The correct option is A.
Explanation
The Indus river system comprises several tributaries that join the main stream from both the left and right banks. The right-bank tributaries are further categorized based on their geographical origin, specifically those originating in the Himalayas and those originating in the Sulaiman ranges of the Trans-Indus region.
- Statement 1 is Correct: The Kurram (Khurram) is a significant right-bank tributary of the Indus. It originates in the Safed Koh mountains, which are part of the broader Sulaiman mountain system in Afghanistan and Pakistan.
- Statement 2 is Correct: The Tochi river, also known as the Gambila river, is a right-bank tributary that flows through the North Waziristan region. It originates in the hills of the Sulaiman range.
- Statement 3 is Correct: The Gomal river is a major right-bank tributary that originates in the eastern slopes of the Sulaiman ranges in Afghanistan and enters Pakistan, eventually joining the Indus.
- Statement 4 is Incorrect: The Zaskar (Zanskar) is a left-bank tributary of the Indus. It originates in the Zanskar Range of the Himalayas (Ladakh) and joins the Indus at Nimmu. It does not originate in the Sulaiman ranges.
Other notable right-bank tributaries originating in the Sulaiman ranges include the Kabul and the Viboa.
Key Takeaway:The Kurram, Tochi, and Gomal are right-bank tributaries of the Indus originating in the Sulaiman ranges, whereas the Zaskar is a left-bank Himalayan tributary.