4. (5 points) Use the Black-Scholes option pricing formula to (1) find the value of a call option on the following stock: Time to maturity =6 months Standard deviation =50 percent per year Exercise price =50 Stock price =50 Interest rate =3 percent (2) Recalculate the value of the option successively substituting one of the changes below while keeping the other parameters: a. Time to maturity =3 months 2 b. Standard deviation =25 percent per year c. Exercise price =$55 d. Stock price =$55 c. Interest rate =5 percent Consider each scenario independently. What do you observe about the changes in option price with respect to the changes in the parameters