Explanation:

The 'guls' or 'kuls' are traditional water harvesting systems prevalent in the Western Himalayas, particularly in regions like Himachal Pradesh. These are diversion channels that carry water from glaciers and perennial streams to villages for irrigation and other uses. Option A, Jaisalmer, and Option B, Jodhpur, are in Rajasthan, where traditional systems like 'Johads' and 'Baoris' are common, but not 'guls' or 'kuls'. Option C, West Bengal, has different traditional water management practices. Therefore, the Western Himalayas is the specific region where these unique diversion channels are found.