Answer:
C) I’m using scarce resources to build the toy trains.
Step-by-step explanation:
In economics, all resources are scarce. Even the richest person in the world or the richest country or the richest company, have a limited amount of money. And that limitation applies to all resources, and the singe resource that is limited equally to everyone is time.
Economics is the science that studies how to allocate scarce resources efficiently.