Regarding the influence of folk music on United States Society, which of the following is false?
选项：

A:.Folk music declined in the 1920s.
B:.Folk music movement in the 1940’s became a positive force for social change in the S.
C:.The social climate resulted in the second folk revival in the 1960’s.
D:.Since the late 199s, economic recession and other social pressures have contributed to a renewed interest in folk music.