13. Consider a bull spread where you buy a 40-strike call and sell a 45-strike call.

Suppose S = \($40\), σ = 0.30, r = 0.08, δ = 0, and T = 0.5. Draw a graph with stock prices ranging from \($20\) to \($60\) depicting the profit on the bull spread after 1 day, 3 months, and 6 months.