Concept:A sill is an intrusive igneous rock feature formed when magma cools below the Earth's surface.Explanation:A sill is created by volcanic activity because it results from the intrusion of molten magma between existing rock layers.Zeugen is a rock pedestal produced by wind abrasion, not volcanic action.Loess is a fine soil deposit carried and laid down by wind.A gorge is a deep valley usually shaped by the erosive action of a river.Thus, among the given features, only a sill has a volcanic origin.Answer:A. Sill