(a) Bhitarkanika Mangroves

(b) Marakkanam Salt Pans

(c) Naupada Swamp

(d) Rann of Kutch 

1. Ans: d

Explanation:

Marshland

• A marsh is a type of wetland, an area of land where water covers ground for long periods of time. Unlike swamps, which are dominated by trees, marshes are usually treeless and dominated by grasses and other herbaceous plants.
• There are three types of marshes: tidal salt marshes, tidal freshwater marshes, and inland freshwater marshes.

Mangroves 

• Mangroves are a group of trees and shrubs that live in the coastal intertidal zone. . There are about 80 different species of mangrove trees. All mangrove trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangroves are coastal swamps bordering major deltas of the country. Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperature 
• The largest amount of mangrove coverage can be found in Indonesia.
• Odisha’s Bhitarkanika National Park, the second-largest mangrove forest in India after the Sundarbans, is known for a successful saltwater crocodile conservation programme. 

Salt Pan

• A salt pan is  formed when pools of seawater evaporate more quickly than they can be replenished by rainfall. During this evaporation process, the minerals and salt ions that were dissolved in the water are left behind, creating a mineral-rich landscape.
• Salt is often the most prevalent mineral in this region, forming a hard white crust on the surface as it accumulates over thousands of years..
• Natural salt pans are different from  the man-made salt pans used in solar salt production  
• Marakkanam is the ancient port town, located at about 120 km from Chennai. The Marakkanam salt pans are spread over an area of 4,000 acres and is one of the largest producers of salt in Tamil Nadu. 
• Nationally, some 60,000 acres have been demarcated as salt pan lands, spread across Maharashtra, Andhra Pradesh, Tamil Nadu, Odisha, Gujarat, and Karnataka. Andhra Pradesh (20,716 acres) boasts the largest expanse of such land, followed by Tamil Nadu (17,095 acres) and Maharashtra (12,662 acres).
• Naupada swamps is in Andhra Pradesh. It is a complex of wetlands consisting of swamps, mud and salt meadows and creek. It is a transitional zone between terrestrial and marine ecosystems and many permanent shallow marine waters on the coastal lines.

Rann of Kutch 

Rann comes from a Hindi word meaning desert, and the region is famous for its marshy salt flats which become snow white when the summer monsoon flood waters dry up. These inhospitable lowlands are resource-rich with minerals and natural gas deposits. Rann of Kutch is the best example of repeated falls in sea level. 

Hence option d is correct.

Read: Previous Year UPSC Environment Questions (PYQs) With Explanation 2023