A University Alumni Office Conducts a Survey of Their Alumni

Multiple Choice

A university alumni office conducts a survey of their alumni to assess changes in attitudes toward the university over time.In the first year of the survey,the alumni office surveys graduates from the year 2007.In the second year of the survey,graduates from the year 2009 are surveyed.The results of the survey indicated very different attitudes of the alumni.The alumni office concluded that attitudes toward the university changed over time.This conclusion

A) fairly describes the differences between 2007 and 2009 graduates.
B) fairly describes changes in attitudes over time among the alumni.
C) may be inaccurate because of the problem of attrition.
D) may be inaccurate because of the problem of noncomparable samples.