Andrea Arena is the owner of 2 Places at 1 Time, a concierge company. She and her staff of 60 perform everyday services such as walking the dog, picking up cleaning, waiting for the repairman, and going to the post office for people who are too busy to perform these simple acts themselves. She is often hired by major corporations to perform services for their harried executives. Her customers have to evaluate the services provided by 2 Places at 1 Time using _____ properties.

a form

b credence

c search

d experience