Explanation:

- Cirque: A cirque is a bowl-shaped, steep-walled mountain basin carved by glacial erosion. It is not formed by wind erosion.

- Stack: Stacks are vertical columns of rock created by coastal erosion, primarily by the action of waves rather than wind.

- Zeugen: Zeugen are ridge formations created by wind erosion. The wind erodes softer materials around harder rock layers, leaving ridges.

- Stack and Zeugen both: Since stacks are formed by coastal processes, not wind, this option is incorrect.

Option 3, Zeugen, is the landform formed by wind erosion.