The right answer is:
A. Investors purchased the stocks with little cash down, if the price dropped the investor had to repay the loan.
Explanation:
Buying on margin is when you take out a loan to buy a stock, this process is also called leveraging your position, it basically means having a collateral.
When you buy on margin the stocks you buy are kept as collateral until you pay off the loan that makes them extremely risky.
