you currently own 100 shares of a stock that has increased in value from $15 to $35 per share. you do not want to sell the stock but want to protect yourself against a large downturn in the market. which of the following is an effective action on your part? a) buy a $30 call option on the stock. b) sell a $30 put option on the stock. c) buy a $30 put option on the stock. d) sell a $30 call option on the stock.