The correct answer is C. Thomas Malthus.
Thomas Malthus was an English economist and demographer who is best known for his theory of population. He argued that population tends to increase geometrically while food supply increases arithmetically, which would lead to overpopulation and poverty.
Adam Smith was a Scottish economist and philosopher who is considered the father of modern economics. He is best known for his book The Wealth of Nations, which was published in 1776.
Charles Darwin was an English naturalist who is considered the father of evolutionary biology. He is best known for his book On the Origin of Species, which was published in 1859.
Stuart Mill was a Scottish philosopher, economist, and politician who is considered one of the most influential thinkers of the 19th century. He is best known for his book On Liberty, which was published in 1859.