Answer:
Since the Alps are in Europe they can not be the largest mountain range in Asia.
The Alps are not In England and the Romans conquered England.
The Alps did not prevent the Roman Empire from taking control of most of Europe that was done by the tribes living in those areas that were not conquered by the Romans.
The correct one is B because if someone wanted to attack the heart of the Empire they had to go over the mountains or around them first which gave the Romans a lot of time to respond.