10. Which one of the following is a bull call spread? A. selling a $20 call and buying a $25 call on the same stock B. buying a $20 call and selling a $25 call on the same stock C. buying a $20 call and selling a $15 call on the same stock D. selling a $20 call and buying a $25 put 11. Which one of the following is a bear call spread? A. buying a $20 call and selling a $15 call on the same stock B. buying a $20 call and selling a $25 call on the same stock C. selling a $20 call and buying a $20 call on the same stock D. selling a $20 call and buying a $25 put 31. Which of the following positions can be used to synthetically create a long position in a European put option on a stock? A) Buy a call on the stock and short the stock B) Buy a put option on the stock and buy the stock C) Sell a call option on the stock and buy the stock D) Sell a call option on the stock and sell the stock