I believe it is A. Sorry if I’m wrong about this. But usually terrorism involves pressuring others into the same beliefs.
It was a physical barrier. Literally a concrete wall.
Austro-Hungarian Empire
The Austro-Hungarian Empire collapsed after World War I, and the subsequent Treaty of Trianon established Hungary's current borders, resulting in the loss of 71% of its territory, 58% of its population, and 32% of ethnic Hungarians.
An abundance of natural resources
