Dun valleys found in the Himachal region are correctly related to what?

Correct answer: Long valleys between Himachal and Shiwalik

The direct answer is A: long valleys between the Himachal and Shiwalik ranges. The Himalayan system has parallel ranges. From the higher Great Himalaya toward the plains, the Himachal or Lesser Himalaya lies before the outer Shiwalik range. Longitudinal valleys occurring between these ranges are called duns or doon valleys. The reasoning is: identify a dun valley → look for a long valley between Himalayan ranges → especially between Himachal and Shiwalik → choose A. Option A is correct; Dehra Dun is a familiar example of this type of valley. Option B is wrong because coral islands of the Arabian Sea refer to Lakshadweep, not Himalayan valleys. Option C is wrong because sand dunes belong to dry desert landscapes such as the Thar, not to the relationship defining duns. Option D is wrong because deltas are depositional landforms at river mouths, especially on the eastern coast, not valleys between Himalayan ranges. Memory cue: dun means a longitudinal valley between the Lesser Himalaya and Shiwaliks.