Artificial rainmaking has been most successful in the ______.

A．the wisdom of older people has been fully used
B．the wisdom of older people is not valued by American society
C．older people's wisdom is an invaluable resource to American society
D．older people are as intelligent as young people

A．tries to justify the youth-oriented, throw-away culture of the American society
B．suggests that people should not retire at the age of 65 or 70
C．thinks that the value of older Americans is gaining increasing recognition
D．thinks young people should give more respect to old people