The Results of a Cross-Sectional Marketing Study to Determine How

Multiple Choice

The results of a cross-sectional marketing study to determine how age affects people's beliefs about family purchases and financial planning were criticized on the ground that the data was influenced by cohort effects. This means that _____.

A) some of the subjects belonged to ethnic minorities
B) the subjects were self-selected by their friends and neighbors
C) the older groups of subjects lived during the Depression
D) only 63% of the questionnaires were returned