The correct answer is option 3 - South America.

Campos and Llanos are two types of Tropical Savanna grasslands, which are characterized by vast expanses of grasses and scattered trees or shrubs. These grasslands are generally found in South America.

Option 1 - Australia is not the correct answer because although Australia does have grasslands, they are not typically referred to as Tropical Savanna grasslands like Campos and Llanos.

Option 2 - Central Africa is not the correct answer because while Africa does have savanna grasslands, Campos and Llanos specifically refer to grasslands found in South America.

Option 4 - East Asia is not the correct answer because Tropical Savanna grasslands are not typically found in this region. East Asia is known for its diverse range of ecosystems, including forests and wetlands, but not specifically Tropical Savanna grasslands.

In conclusion, Tropical Savanna grasslands, specifically Campos and Llanos, are generally found in South America.