According to the author, when young families are i

单项选择题

TEXT C
For a long time we have worked hard at isolating the individual family. This has increased the mobility of individuals; and by encouraging young families to break away from the older generation and the home community, we have been able to speed up the acceptance of change and the rapid spread of innovative behavior. But at the same time we have burdened every small family with tremendous responsibilities once shared within three generations and among a large number of people—the nurturing of small children, the initiation of adolescents into adulthood, and care of the sick and disabled and the protection of the aged. What we have failed to realize is that even as we have separated the single family from the larger society, we have expected each couple to take on a range of obligations that traditionally have been shared within a family and a wider community.
So all over the world there are millions of families left alone, as it were, each in its own box —parents faced with the specter of what may happen if either one gets sick, children fearful that their parents may end their quarrels with divorce, and empty-handed old people without any role in the life of the next generation.
Then, having reduced little by little to almost nothing the relationship between families and the community, when families get into trouble because they cannot accomplish the impossible, we turn their problems over to impersonal social agencies, which can act only in a fragmented way because they are limited to patchwork programs that often are too late to accomplish what is most needed.
Individuals and families do get some kind of help, but what they learn and what those who work hard within the framework of social agencies convey, even as they try to help, is that families should be able to care for themselves.

According to the author, when young families are isolated, ______.

A．old people can easily accept the change
B．people can move from place to place
C．individuals can hardly become innovative
D．economy develops at high speed