A steppe is a grassland plain without trees (except near water bodies). The Russian steppe is similar to African savannas - both are tropical/subtropical grassland ecosystems. Swiss mountains (A) are Alpine - wrong topography. Middle Eastern deserts (B) are arid with sandy/rocky terrain - wrong biome. South American rainforests (C) are dense tropical forests - completely different. African savannas (D) are the correct match - both are grassland ecosystems with similar topography.