Martinez opens a brokerage account and purchases 4,000 shares of Aston Villa at $35 per share. He borrows $45,000 from his broker to help pay for the purchase. The interest rate on the loan is 11%. a. What is the margin in Martinez's account when he first purchases the stock? b. If the share price falls to $18 per share by the end of the year, what is the remaining margin in his account? If the maintenance margin requirement is 35%, will he receive a margin call? c. What is the rate of return on his investment