The correct option is Esker.
Explanation
Glacial landforms are classified based on the geomorphic processes that create them. Erosional landforms result from the abrasive action of moving ice and plucking of rock, whereas depositional landforms are created by the accumulation of glacial debris (till) or sediment carried by meltwater.
- Cirque (Erosional): These are deep, bowl-shaped depressions with steep walls found at the head of a glacial valley. They are formed by the erosive action of ice plucking and abrasion.
- Horn (Erosional): A horn is a sharp, pyramidal peak formed when three or more cirques erode backwards into a single mountain summit.
- Arete (Erosional): An arete is a sharp, knife-edged ridge that separates two adjacent cirques or glacial valleys. It is formed by the simultaneous erosion of the valley walls on both sides.
- Esker (Depositional): An esker is a long, winding ridge of stratified sand and gravel. It is formed by the deposition of sediment by meltwater streams flowing in tunnels underneath or within a glacier. Since it is formed by accumulation rather than removal of material, it is not an erosional landform.
Key Takeaway: Cirques, Horns, and Aretes are classic examples of glacial erosion, while Eskers, Drumlins, and Moraines are landforms resulting from glacial deposition.