Correct Option (D):
The Rann of Kutch, located in Gujarat, is an extensive seasonally marshy region characterized by vast salt flats. Its formation is primarily attributed to repeated marine transgressions (rise) and regressions (fall) in sea level over geological periods. During the monsoon, the area is submerged, transforming into a saline marsh, which then dries up to form extensive salt flats in the dry season. This unique geomorphological feature exemplifies the impact of fluctuating sea levels on coastal landforms.
Incorrect Options:
Bhitarkanika Mangroves: Located in Odisha, these are primarily deltaic mangrove ecosystems formed by the depositional activities of the Brahmani and Baitarani rivers. Their formation is not directly linked to repeated falls in sea level.
Marakkanam Salt Pans: Situated in Tamil Nadu, these are predominantly artificial salt production areas, not natural marshlands formed by geological processes involving sea-level fluctuations.
Naupada Swamp: This swamp is located in Andhra Pradesh. While it is a marshy area, its formation is not attributed to repeated changes in sea level, which is the specific condition mentioned in the question.