What was a result of investors selling stocks at much lower prices than they bought them, ultimately contributing to the stock market crash? a) people who normally did not invest began buying stocks because they were so cheap. b) businesses had to buy back their own stocks so investors would not sell them too cheaply. c) investors who borrowed could not pay back their loans, so people rushed banks to withdraw their savings. d) the investors made a large profit upfront because they were able to sell so quickly; however, they were unable to buy the stocks back.