Answer:
all useful resources are limited in their supply.
Livelihood
1. Means of support of subsistence
2. The quality or state of being lively.
“Many fishermen believe that the new regulations threaten their livelihoods”
Reasons to visit California on summer vacation and why seatbelts should be required both are trying to convince you of something. A speech at a retirement celebration is more of an entertainment thing so I think the best answer would be how to change the oil in your car because it is 'informing' you of something