Which of the following statements is true? Select one: a. For both calls and puts an increase in the exercise price will cause an increase in the option price. Ob. For calls, but not for puts, an increase in the time to maturity will cause an increase in the option price. O C. For puts, but not for calls, a decrease in the price of the underlying stock will cause an increase in the option price. O d. If the riskiness of the underlying asset decreases, then the Value of both the put and the call option will increase. O e. For both calls and puts an increase in the risk free rate will cause an increase in the option price