What is the largest rainforest in the world?

The Amazon Rainforest is recognized as the largest rainforest in the world, spanning over 5.5 million square kilometers across several countries in South America, including Brazil, Peru, and Colombia. This vast area hosts an incredibly diverse range of flora and fauna, making it one of the most biodiverse ecosystems on the planet. The Amazon plays a crucial role in regulating the Earth's climate and is often referred to as the "lungs of the planet" due to its ability to produce significant amounts of oxygen and absorb carbon dioxide.

The other options represent substantial forests but do not match the size and ecological significance of the Amazon. The Congo Rainforest is the second-largest rainforest, covering about 3.6 million square kilometers, primarily in Central Africa. The Taiga is actually a boreal forest, characterized by coniferous forests, and spans across northern regions of the globe, rather than being a tropical rainforest. The Valdivian Rainforest, located in Chile and Argentina, is significant but much smaller in comparison to the Amazon. Therefore, the Amazon Rainforest holds its title as the largest rainforest due to its expansive area and vital environmental contributions.