FFT Consider the following risk-neutral pricing formula for a European Digital Call: Co = [e-rT1{ST>K}] (a) Derive the pricing formula that can be used to price European Digital Call options using the characteristic function of a stochastic process. NOTE: Your answer should have a single integral and be a function of the characteristic function and K. (b) Describe two approaches for calculating the final integral and the trade-offs between them. (c) Discuss how you would use this pricing formula to create an approximation for an American Digital put option. The payoff for an American Digital put option can be written as: Po = = E [eT1{Mr