Rose Riley's parents have booked and paid for a family trip to Aspen, Colorado, during her spring break. Rose's friends recently decided to drive to Destin, Florida, for spring break. Rose needs to decide whether to join her parents in Aspen or drive to the beach with her friends. The opportunity costs of joining her friends on the trip to Destin include each of the following except:____.
a. her parents' anger if she skips the family trip to Aspen.
b. her contribution to gas money for the drive to Destin.
c. the hotel costs she will split with her friends in Destin.
d. the ski lift ticket her parents have already purchased for her.