The correct answer is letter "C": the invisible hand.
Explanation:
In Economics, the term "invisible hand" refers to the belief that markets are created according to the demands and needs of individuals who take advantage of opportunities without the need for the intervention of other parties like a government. The term was coined by Scottish Enlightenment thinker Adam Smith (1723-1790) in his book "<em>An Inquiry into the Nature and Causes of the Wealth of Nations</em>" (1776).
