Who described State as an organism? 

The correct answer is Ratzel.
Important PointsThe concept of the state as an organism was primarily introduced by Friedrich Ratzel, a German geographer and ethnographer, often considered one of the founders of modern political geography.

• In the late 19th century, Ratzel developed the idea of the state as a living organism, arguing that it needed to consume territories (a theory known as Lebensraum or "living space") to sustain itself, similarly to how an organism needs nutrients.
• Wilhelm von Humboldt was a Prussian philosopher and linguist and he was more focused on language, education and individual freedom rather than the concept of the state as an organism.
• Isaiah Bowman was an American geographer, known for his work in economic and political geography, but he is not primarily associated with the concept of the state as an organism.
• Halford Mackinder, a British geographer, is known for his geopolitical theories, specifically the Heartland Theory, which relates more to the strategic importance of geographic location in international relations, rather than viewing the state as an organism.