In 1975, Cialdini and colleagues asked college students to spend 2 hours chaperoning a group of children on a field trip to the zoo. Only _____ agreed to this request

However, after first asking another group of college students to volunteer every week, for a minimum of two years, _______ agreed to the second request to chaperon the zoo trip because of the door-in-the-face technique.
a. 50%; 17%
b. 17%; 100%
c. 100%; 50%
d. 17%; 50%

Answer: D