Suppose Vicky decides to see the hippopotamuses. Which result would be a cost?
A: Vicky will spend more time walking to the hippopotamuses. They are on the other side of the zoo, but the storks are close by.
B: Vicky will enjoy seeing the hippopotamuses more than she would have enjoyed seeing the storks.
This result is a cost. It involves giving up or spending something that Vicky wants or needs:
Vicky will spend more time walking to the hippopotamuses. They are on the other side of the zoo, but the storks are close by.