Answer:
a. It controlled land bordering the Mediterranean Sea.
Explanation:
The Byzantine Empire or Byzantium was the eastern part of the Roman Empire that survived throughout the Middle Ages and the beginning of the Renaissance. This empire was located in the eastern Mediterranean. Its capital was in Constantinople.
Throughout its long history, the Byzantine Empire suffered numerous setbacks and losses of territory, especially during the Roman-Sassanid wars, Byzantine-Norman wars, and the Arab-Byzantine wars. Although its influence in North Africa and the Middle East had declined as a result of these conflicts, it continued to be an important military and economic power in Europe, the Middle East, and the Eastern Mediterranean during most of the Middle Ages.
At the end of the 10th century, it only controlled Greece, Anatolia, and Southern Italy.
