Dr Sanjay Is Studying Whether His Racism Awareness Program Increases

Dr. Sanjay is studying whether his racism awareness program increases his research participants' awareness of issues of race and ethnicity in his city. On Monday, he gives an attitude survey to his participants to gauge their awareness. On Tuesday through Thursday, he puts them through his program. On Wednesday, a local predominantly black church is firebombed and the KKK claims responsibility. On Friday, Dr. Sanjay gives his awareness survey again and finds awareness of racial issues has increased dramatically. This example illustrates the possibility of ______________ as a plausible rival explanation.

A) History
B) Maturation
C) Regression artifact
D) Differential selection