This result is a cost. It involves giving up or spending something that Celine wants or needs:
Celine will give up the chance to look at the oak tree. She thinks it would have looked more beautiful than the lilies.
Suppose Celine decides to plant the lilies. Which result would be a cost?
A: She will save some space. The lilies will use up less space than the oak tree would have used up.
B: Celine will give up the chance to look at the oak tree. She thinks it would have looked more beautiful than the lilies.