8. Write a VBA program to show the construction of a bull and bear spread, first using calls only and then using puts only. Also plot both the call spread and put spread in both bull and bear phases. Explain your observation for the difference in the initial cost of call and put spreads.

Assume the following parameters:

S(0) 5 100; T 5 1; r 5 8%; σ 5 30%; Spread 5 10%.