Which event triggered the onset of the great depression of the 1930s?

The Great Depression lasted from 1929 to 1939 and was the worst economic depression in the history of the United States. Economists and historians point to the stock market crash of October 24, 1929, as the start of the downturn. But the truth is that many things caused the Great Depression, not just one single event

The answer is C.  stock market crash