Southern Europe's landscape is mostly mountainous. The fourth optios is correct.
The landscape in Southern European countries is characterized by the presence of important montainous chains and by the Mediterranean weather. In Southern European you can find the Alps,which lie in the territories of France, Germany, Italy and Switzerland, as well as important mountain chains in Spain (the Pyreness and Sierra Nevada), in Italy (Apennine mountains from North to South) and in the whole country of Greece, including some of its islands.