Please help! I'm stuck between A and D.

Use the map below to answer the following question:

What is a geographical difference between southern Europe and northeastern Europe?

A. Southern Europe has a large number of mountains, while northeastern Europe is mostly flat.
B. Southern Europe is mostly flat, while northeastern Europe is mostly mountainous.
C. Southern Europe is a land of large rivers and lakes, while northeastern Europe is dry and arid.
D. Southern Europe has few rivers and lakes, while northeastern Europe has more lakes than forests.