Explanation:

• Cirque: A cirque is a landform primarily shaped by glacial activity rather than wind erosion. It is a bowl-shaped depression with steep sides that is carved into mountains or highlands by the action of glaciers.

• Stack: A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, formed by wave erosion. So, it's a product of water erosion, not wind.

• Zeugen: Zeugen are table-shaped landforms created by wind erosion. These are common in arid and semi-arid regions where wind plays a significant role in shaping the landscape.

Therefore, among the given options, only Zeugen are formed by wind erosion,