The answer is D: Be prepared to cope with inevitable extreme poverty and malnutrition
Thomas Robert Malthus was a scholar and an English cleric, specialized in the fields of political economy and demography. Thomas became famous for his 1798 essay on population growth in which he argued that population multiplies geometrically and food arithmetically.
He was also famous for his 1798 book, An Essay of the Principle of Population. In this book, he argued that human beings had a natural tendency to utilize abundance for population growth. It is in this book that he argued that two types of checks hold population within resource limits: Preventive checks and Positive checks.
Positive checks included diseases and war, and hunger while the preventive checks included birth control, celibacy, and postponement of marriages.