(a) Petro Asia Inc. opened an account with Fista Broker to short-sell 2,000 shares of Maya Inc at $40. Fista required 50% initial margin. A year later, Maya's share price rises to $50 and the stock has paid a dividend of $1 per share. (i) What is the margin in Petro Asia's account at the beginning? (ii) If the maintenance margin requirement is 30%, will Petro Asia receive a margin call after one year? (iii) What is the rate of return on the investment for Petro Asia Inc. at the end of one year