一道英语阅读题

题目

一道英语阅读题
The Europeans who left their homeland in the 18th centuries and settled their homes in north America are referred to (指的是) as early settlers.Early settlers who came from the eastern parts of the present U.S.A.were used to having many trees around,so they found it rather hard to get used to living in a treeless place like the state of Nebraska.When they first settled down in Nebraska,they needed large quantities of wood for building housee,making fires and doing many other things.Therefore they started many tree－planting plans that went on for years and years.Finally in 1872,a newspaperman named J.Sterling Morton had an idea:Why not have a special day set aside for planting trees?So Arbor Day was born on April 10th,1872,and the first Arbor Day was celebrated.The state government announced that it would give prizes to individuals(个人)and groups that planted the most trees.On that first day,more than 1,000,000 trees were planted in Nebraska.In this way Nebraska has been affore

答案

如果答案是D的话,那应该是因为early settlers指的既是europeans又是people who came from the eastern part of USA 这样就可以解释清楚了