Ellie Is a Girl Scout Who Goes Door to Door

Ellie is a Girl Scout who goes door to door selling cookies.She finds that,by asking people to buy one box of cookies so that she can go on a field trip,they often buy more when she later tells them that she is competing with other scouts to win an even larger trip.On average,Ellie finds that about 25% of people buy more than one box of cookies,although she has no real way of predicting which customers will purchase a larger order.Ellie is using the _____ sales technique and her behaviour is reinforced according to a _____-ratio schedule.

A) foot-in-the-door;fixed
B) foot-in-the-door;variable
C) door-in-the-face;fixed
D) door-in-the-face;variable