The U.S. government did that because of the Great Depression. The government strengthened the economy by paying special attention to it during the course of several decades. It began with the New Deal promoted by President Franklin Delano Roosevelt. The main point of the government´s larger role in the U.S. economy was to the rapid growth money supply to encourage spending and move forward to the market.
The correct answer is a. evolution. Darwin was the scientist behind the theory of natural selection, one of the main mechanisms behind evolution (next to sexual selection).
