Which phenomenon would most likely result in the formation of valleys?

Plate divergence refers to the process in which two tectonic plates move away from each other. This movement can create new landforms, particularly in oceanic regions, where it often leads to the formation of mid-ocean ridges and rift valleys. As the plates separate, the tectonic activity can cause the land to sink or stretch, leading to the development of valleys in the rift zone. This geological process is responsible for the creation of distinct valley features, particularly in areas such as the East African Rift, where the continental crust is being pulled apart.

In contrast, while earthquakes can cause ground movement and sometimes result in localized depressions or shifts in the landscape, they are not primarily responsible for the large-scale formation of valleys. Deforestation impacts ecosystems and can alter land use but does not inherently create valleys. Flooding can temporarily shape land and create floodplains, but it does not typically result in the long-lasting formation of valleys compared to the geological processes associated with plate divergence.