Every Cup of Dannon Yogurt Contains a Letter Under the Lid

Multiple Choice

Every cup of Dannon Yogurt contains a letter under the lid seal.Customers who collect lids and spell certain words win a prize if they send the letters and the official order form back to Dannon.Within 90 days,these customers will receive the prize of their choice.A(n) _____ will occur when a customer mails in his or her lid seals for a prize.

A) synergy
B) sublimation
C) exchange
D) entropy
E) reciprocity