单选题

　　[阅读选择]Northern Europeans are willing to pay a lot of money and put up with a lot of inconveniences for the sun because they have so little of it. Residents of cities like London， Copenhagen， and Amsterdam spend a lot of their winter in the dark because the days are so short， and much of the rest of the year in the rain. This is the reason the Mediterranean has always attracted them. Every summer， more than 25 million people travel to Mediterranean resorts and beaches for their vacation. They all come for the same reason： sun！

　　In the paragraph， cities like London， Copenhagen， and Amsterdam are mentioned_____.

　　A.to show that they are not good cities in terms of geography and climate

　　B.to tell us how wealthy their residents are

　　C.to suggest that these cities lack places of historic interest and scenic beauty

　　D.to prove that they have got more tourism than they can handle