Suppose Jen decides to plant the birch tree. Which result would be a cost?
Jen will get to look at the birch tree. She thinks it will look more beautiful than the sunflowers would have looked. The birch tree will use up more space than the sunflowers would have used up.
Jen is deciding whether to plant sunflowers or a birch tree in her backyard. She wants to make her backyard more beautiful. But she also wants to leave space for doing fun things.
Before you decide to do something, it is often helpful to list costs and benefits.
Costs are what you give up or spend when you decide to do something. Costs involve giving up things that you want or need.
Benefits are what you gain or save when you decide to do something. Benefits involve gaining something that you want or need.
This result is a cost. It involves giving up or spending something that Jen wants or needs:
The birch tree will use up more space than the sunflowers would have used up.