In this question, we are asked about the term used for grassland in a specific region. The correct answer is option 2 - South America. Grassland in South America is commonly referred to as `Pampas`.
Option 1 - Africa is incorrect because the term used for grassland in Africa is `savanna`.
Option 3 - United Kingdom is incorrect because the term used for grassland in the United Kingdom is `downs` or `moorland`.
Option 4 - The USA is incorrect because the term used for grassland in the USA is `prairie`.
Therefore, the correct term for grassland in South America is `Pampas`.