Which answer choice describes two central ideas of the article? (A) A panic occurred when the stock market began to crash in October of 1929; it is easy to see now how remaining calm would have helped prevent further disaster. (B) The period of economic growth and prosperity was called the Roaring '20s; investors were putting all of their money and their hopes in the stock market continuing to rise. (C) A number of actions by experts and investors contributed to the stock market crash of 1929; most failed to predict how events would lead to the stock market crash. (D) The stock market crash was an economic disaster that happened just before the Great Depression of the 1930s; many people lost their homes as well as their jobs or businesses.