Answer:
A. The challenges and difficulties of feeding the world's population
Explanation:
Lifeboat Ethics is a metaphor for asset distribution proposed by the ecologist Garrett Hardin in 1974.
Hardin's metaphor depicts a raft bearing 50 individuals, with space for ten more. The raft is in a sea encompassed by a hundred swimmers. The "morals" of the circumstance originate from the issue of whether swimmers ought to be taken on board the raft.
Delete usual. Custom and usual do not flow together and a custom is already a usual thing, just like tradition.
