Which of the following is true (could be more than one): Mark-to-market of futures contracts is the process of realizing gains and losses each day as the futures contract changes in price Futures contracts require an initial margin requirement be paid A stock has a spot price of $5s. Its may options are about to expire. One of its puts is worth $5 and one of its calls is worth S10. The exercise price of the put must be $55 and the exercise price of the call must be $50 Writing a put option results in a potentially limited gain and a potentially unlimited loss The buyer of a call option on stock benefits if the underlying stock price rises or if the volatility of the stock's price increases