Which statement best reflects the permeability of physical boundaries?

• A. They follow natural features and are often less permeable, but crossing remains possible.
• B. They are always impermeable and cannot be crossed.
• C. They are defined solely by language and religion.
• D. They determine only airspace.

Answer: (A)

Permeability describes how easily a boundary can be crossed by people, goods, or ideas. Physical boundaries often follow natural features like rivers, mountains, or coastlines, which makes them harder to cross than open space, but not impossible. Crossing remains possible through bridges, tunnels, ferries, or if policies and technology permit passage. So the statement that physical boundaries follow natural features and are often less permeable, but crossing remains possible, best captures this nuance. Other options misrepresent the idea by claiming boundaries are absolute walls, defined only by language or religion, or that they concern only airspace.