The correct answer is C) mountainous terrain.
The geographic feature that hindered the Byzantine Empire from expanding North of Italy was a mountainous terrain.
This mountain range is known as the Alps. The Alps are the highest mountains in Europe and the largest mountain range in the continent, as you can see in the map attached. The Alps stretch along Europe with 750 miles. The Alps cross Italy, Switzerland, Germany, France, Monaco, Austria, Slovenia, and Liechtenstein. Although the Romans had settlements in the region and some military post, the Alps are a physical barrier difficult to cross. That is why the geographic feature that hindered the Byzantine Empire from expanding North of Italy were the Alps.
