What real-world issue is the author referring to by using a lifeboat metaphor in "Lifeboat Ethics: The Case Against Helping the Poor"?

AStarvation, in regard to how many people need food supplied by other countries in order to survive
BRacism, in regard to how many people use prejudice to decide who gets food and who doesn't
CReproduction, in regard to how poorer nations have a much higher rate of population growth
DForeign policy on immigration, in regard to how many people can live in a country and still preserve its resources

The real-world issue that the author is referring to by using a lifeboat metaphor in "Lifeboat Ethics: The Case Against Helping the Poor" is the Foreign policy on immigration, in regard to how many people can live in a country and still preserve its resources

Explanation:

"Lifeboat Ethics: The Case Against Helping the Poor" has as main idea the conflict that poorer countries represent an unbalanced consumption of resources for richer countries, and it is important to take in consideration how far can this aid to poorer countries go without affecting the ones that are native from the rich countries.