What natural feature serves as the border between France and Germany?

The Rhine River serves as the natural border between France and Germany, making it the correct answer. This river is significant not only for its geographical positioning but also for its historical and economic importance in Europe. Stretching approximately 1,230 kilometers, it flows from the Swiss Alps through Germany and the Netherlands, eventually emptying into the North Sea. The Rhine has historically been a critical trade route and has shaped the cultural and economic interactions between the countries it flows through.

In contrast, the Seine River primarily flows through the Paris region and does not form a border between France and Germany. The Danube River, while one of Europe’s longest rivers, flows through several Central and Eastern European countries and does not serve as a direct border for the two nations in question. Similarly, the Rhône River is an important river in southeastern France but flows entirely within France, not creating a natural border between France and Germany.