Here are the answers to your questions based on economic concepts:
1. **Marginal Utility**: The added satisfaction that a consumer gets from having one more unit of a good or service.
2. **Scarcity**: The inability to satisfy all wants at the same time. All resources and goods are limited. This requires choices to be made.
3. **To gain the most satisfaction possible**: This is what it means to maximize utility.
4. **Scarcity**: The