Which of the following is the correct formula to find the present value of the following series of cash flows: $100 recieved in one year and $200 received in three years. Assume a discount rate of 7 percent.

a. PV = 100/(1+0.07)¹ x 200/(1+0.07)³

b. PV = 100 x (1+0.07)¹ + 200 x (1+0.07)³

c. PV = 100/(1+0.07)⁴ + 200/(1+0.07)²

d. PV = 100/(1+0.07)¹ + 200/(1+0.07)³

e. None of the above responses are correct.