The correct answer is option 2: Taiga. The term "Taiga" is specifically associated with Siberia and refers to the vast coniferous forest that covers much of the region.

Option 1: Selva is a term used to describe the dense tropical rainforests found in South America. It is not associated with Siberia.

Option 3: Pampas is a term used to describe the vast grassy plains found in South America, particularly in Argentina and Uruguay. It is also not associated with Siberia.

Option 4: Savanna is a term used to describe a type of grassland ecosystem characterized by a mixture of grasses and scattered trees. While savannas can be found in various parts of the world, they are not typically associated with Siberia.

Therefore, the correct term associated with Siberia`s natural vegetation is Taiga. The Taiga is characterized by dense forests of evergreen coniferous trees, such as spruce, fir, and pine, and is adapted to the cold and harsh climate of the region.