阅读下列短文，从每题所给的四个选项（A，B，C， D ）中，选出最佳选项。
A
Recent studies suggest that family arrangements in Western societies have not changed as much in the last few centuries as is generally believed. Yet most sociologists agree that in modern societies, there are fewer opportunities for friendship and support from relatives. Parents and children often live apart from other relatives, and seldom visit them. Also, the family moves when a parent accepts a job in another place or when it decides to live in a better neighbourhood. Together, loneliness and mobility (迁移) force immediate family members to depend heavily on one another for affection and companionship.
Because the family is one of the few ongoing sources of affection and companionship in modern societies, a high percentage of people continue to marry, even though it is possible for a single man and woman to live
