What is North Dakota's state tree?

North Dakota's state tree is the American Elm. This choice is correct because the American Elm has historical significance in the state, particularly due to its resilience and adaptability to the northern climate. The species is known for its stately appearance and has been widely planted in urban areas as a shade tree. Its ability to thrive in diverse soil conditions and withstand harsh weather makes it a fitting representation of North Dakota's natural heritage.

While pine, maple, and oak trees are also significant in North Dakota's ecosystem, they do not hold the same official designation as the state tree. A variety of tree species are present in the state, but the American Elm has been specifically recognized for its cultural and ecological importance, making it the correct answer in this context.