Which process forms a 'U-shaped valley'?
- River erosion
- Glacial erosion
- Wind erosion
- Coastal erosion
Answer: Glacial erosion
U-shaped valleys are formed by glacial erosion, where glaciers carve wide, steep-sided valleys with flat bottoms. In contrast, river erosion creates V-shaped valleys. U-shaped valleys are common in the Himalayas and Alps.