Why Do Researchers Use Role-Playing in Investigations of Attitude Change

Why do researchers use role-playing in investigations of attitude change?

A) because people show greater attitude change after writing a persuasive speech than after reading one
B) because people show less attitude change for self-generated arguments than for arguments provided by others
C) because people show less attitude change after reading a persuasive argument when they expect to persuade someone else
D) because people show more attitude change after role-playing if they are low in need for cognition.