Answer: Opportunity cost
Step-by-step explanation:
Opportunity cost is basically arranging your schedule from that which is of great importance to the next, till the least important. It is understood that most of our activities are not giving same energy, especially when we understand some better than the others, this is where opportunity cost comes in, allowing you to arrange all activities from that which needs much attention to that which needs less, this is what Felix was doing that his wife needed to understand