Here's why:

* Geosphere: This sphere encompasses all the solid, non-living parts of the Earth, including rocks, minerals, soil, and landforms like mountains, valleys, and plains.

* Atmosphere: This sphere is the layer of gases surrounding the Earth.

* Hydrosphere: This sphere includes all the water on Earth, such as oceans, lakes, rivers, and groundwater.

* Biosphere: This sphere encompasses all living organisms on Earth, from plants and animals to microscopic bacteria.

Therefore, the geosphere is the only sphere that inherently contains landforms.