Answer:
B) Extremely cold climate conditions made it difficult to live in the region
Explanation: In places where there are countless mountain ranges, there is bound to be isolation to the point where the people that already reside there would develop their own language, culture, and mannerisms. Northern Europe is filled with mountains and cold climate. Many people from other regions in Europe would have a hard time adjusting to the harsh conditions like the natives.
It’s actually not any of those it’s osmotic flow of water :)
I think you wanted to know whether the statement in question is true or false. Based on this assumption, i am answering the question. It is a true fact that the Danube River is navigable and thus connects many of the countries of the European continent. I hope that the answer has come to your help.