问题：

[单选,材料题]

回答下面的题目:
The American Family
In the American family the husband and wife usually share important decision making. When the children are old enough, they take part_________(51). Foreigners are often surprised by the permissiveness of American parents. The old rule that "children should be seen and not heard" is rarely_________(52), and children are often allowed to do what they wish without strict parental_________(53). The father seldom expects his children to obey him_________(54) question, and children are encouraged to be independent_________(55) an early age. Some people believe that American parents carry this freedom_________(56) far. Others think that a strong father image would not_________(57) the American values of equality and independence. Because Americans emphasize the importance of independence, young people are expected to break_________(58) their parental families by the time they have_________(59) their late teens or early twenties. (60), not to do so is often regarded as a failure, a kind of weak dependence.
This pattern of independence often results in serious_________(61) for the aging parents of a small family. The average American is expected to live(62) the age of 70. The job-retirement age is _________(63) 65. The children have left home, married, and_________(64) their own households. At least 20 percent of all people over 65 do not have enough retirement incomes. _________(65) the major problem of many elderly couples is not economic. They feel useless and lonely with neither an occupation nor a close family group.

A . But
B . Therefore
C . In contrast
D . Even if