As Part of a Tenth-Grade "Social Living" Course, a Teacher

As part of a tenth-grade "Social Living" course, a teacher has a guest speaker come to his classroom to talk about the dangers of drug use. The guest speaker is a former hardcore drug user, who became involved in serious criminal behavior as a result of his use, spent many years in jail, later entered a drug rehabilitation program, and finally cleaned up his act. All things being equal, is the guest speaker likely to be more effective or less effective than the teacher would have been at communicating the dangers of drug use?

A) much less effective
B) slightly less effective
C) about the same
D) somewhat more effective