Darcy and Gus are a married couple living in Shreveport. Their families also live there. They have recently had their first child and have taken advantage of grandparents being nearby to watch the baby while both parents go to work. Gus has been offered a higher-paying job in Baton Rouge. Moving would mean their income could increase, but they would have to either start paying for childcare, or Darcy would have to give up working to stay home to care for the baby. They are weighing their options and trying to decide what to do. What is the scenario involving Darcy and Gus an example of?

command economics
decreased value
scarcity
opportunity cost