Problem 9.1. An investor buys a European put on a share for 83. The stock price is $42 and the strike price is $40. Under what circumstances does the investor make a profit? Under what circumstances will the option be exercised? Draw a diagram showing the variation of the investor's profit with the stock price at the maturity of the option. Problem 9.2. An investor sells a European call on a share for $4. The stock price is $47 and the strike price is $50. Under what circumstances does the investor make a profit? Under what circumstances will the option be exercised? Draw a diagram showing the variation of the investor's profit with the stock price at the maturity of the option. Problem 9.4. Explain why margins are required when clients write options but not when they buy options. Problem 9.6. A company declares a 2-for-1 stock split. Explain how the terms change for a call option with a strike price of $60