Explanation:

About Pantanal Wetlands

• It is the world’s largest tropical wetlands.
• It sprawls across three South American countries i.e. Bolivia, Brazil and Paraguay and supports millions of people there, as well as communities in the lower Rio de la Plata Basin.
• The Pantanal derives its name from the Portuguese word for 'swamp'.
• Roughly 80% of the Pantanal floodplains are submerged during the rainy seasons, nurturing a biologically diverse collection of aquatic plants and helping to support a dense array of animal species.

Hence option 4th is correct.