Why did so many investors begin to sell off their stocks, causing black thursday and leading to the beginning of the great depression? they needed the money for other investments. there were too many scams involving stocks. companies were losing business and their money. it was better to keep cash on hand for emergencies.

I believe that C is the correct answer.

C, Companies were losing business and their money, is the right answer.

Explanation:

24th October 1929 witnessed a record of the number of shares traded on the New York stock exchange. This selling was made by panicking investors, indicating the start of the market collision which leads to the Great Depression. Within,  companies acquired more funds to grow production to produce more goods, which failed since now the demand for the goods was so weak which failed the companies. Eventually, when the depression hit, many corporations had to make workers unnecessary to cut costs.

c) they were beaten and fired from their jobs.