7. You open a brokerage account and buy 300 shares of Copperfield Inc at $40/ share. You borrow $4,000 from your broker to help pay for the purchase, and the interest rate on the margin loan is 8%. A. What is the margin in your account at the time you purchase the stock? B. After one year, if Copperfield drops to $30 /share, what will your remaining margin amount be? Note: Make sure to account for the interest owed on the broker's loan. C. Suppose the maintenance margin is 30%. Will the drop to $30 trigger a margin call? Explain. D. Suppose Copperfield is at $30 one year after your purchase of the stock. Calculate your return on investment. Assume that Copperfield Inc pays no dividends. E. Ignoring interest owed to the broker, how low can the share price drop before a margin call is triggered