When Robert Cialdini and His Colleagues (1975)first Asked Participants to Commit

When Robert Cialdini and his colleagues (1975) first asked participants to commit to a two-year volunteer stint at a juvenile detention center,those who refused that initial request were more likely than others to agree to take problem adolescents on a two-hour trip to the zoo.Why?

A) Participants felt guilty for refusing the large initial request.
B) Participants wanted to reciprocate the experimenter's cooperation.
C) Participants wanted to reward the experimenter for his persistence.
D) Participants experienced psychological reactance to the first large request.
E) Participants wanted to help the juvenile detention center.