Question

Students on two college campuses serve as treatment and control groups in a study investigating the effectiveness of an alcohol-abuse prevention campaign. A well-known student on one of the campuses dies of alcohol intoxication in the course of the study; students on the other campus did not learn of the student's death. The reaction of other students to the student's death on their campus could represent a potential threat to the internal validity of the study called
A. history.
B. selection.
C. additive effects of selection and history.
D. additive effects of selection and maturation.

Answer

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