What Is/are the Lesson(s)learned from the Stock Market Crash of 1929

Multiple Choice

What is/are the lesson(s) learned from the stock market crash of 1929?

A) Statements and opinions of federal officials can and do impact consumer and business optimism and pessimism regarding stocks and other financial markets, leading to volatile buying and selling behaviors.
B) Portfolio diversification is important.
C) One segment of the aggregate market economy can experience events that impact the economy?as a whole.
D) Reflection, analysis and evaluation are often required to understand why an event occurred and what can be done to prevent it from happening in the future.