Read the Following Four Statements About Social Mobility in the United

Read the following four statements about social mobility in the United States. Which statement is NOT correct?

A) Overall, social mobility has been fairly high.
B) Within a single generation, most social mobility involves jumping from one class level to another rather than making small movements within one class.
C) Over the long term, there has been more upward than downward social mobility.
D) Upward social mobility was more pronounced before 1970 than it has been since 1970.