The correct answer is the Law of Competition.
According to Carnegie’s beliefs, the element that ensures the survival of the fittest in every department and is essential to the future progress of the man is the Law of Competition.
In 1889, Dale Carnegie wrote “The Gospel of Wealth”. In that document, he refers to the law of competition. In his essay, he talks about that the law of competition can be difficult for the individual but is the only one that guarantees the survival of the fittest in every department.