阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
Settled by the Celts, invaded by the Romans and the Normans, and ruled by the English, Wales' population has regularly changed over the ages. Wales, particularly South Wales, became a melting pot (熔炉) of European nationalities and cultures. At first workers from England, Ireland and the rural areas of Wales rushed into the coal mines of South Wales. By 1911, workers from Ireland, Italy and Spain had joined the industrial workforce (劳动大军) there. Many of these newcomers were prepared to work for less pay.
But during this period, workers, dissatisfied with regular pay cuts, poor safety, returned to the land. In 1891, the rural population of Wales was about 616,000 and by 1911 just over 649,000 people lived and worked in these areas.
The rural population continues to grow slowly even today. People from richer parts of the UK, particularly southern England, are buying holiday homes in Wales. In some areas this has led to a lack of housing for local people. This, combined with the lack of employment in rural Welsh communities, has started a new movement of people in search of jobs and homes into the towns and cities of Wales and to other parts of the UK and Europe.
As so many Welsh people have moved to other countries over the last 200 years, it's really no surprise that many visitors come to see friends and relatives. These visitors strengthen their links to their land of origin and continue to support the Welsh's development. During the hot summer days, about 28% of the visitors visit the countryside and nearly 70% visit the seaside.
