(b) How to replicate the payoff of a bond (riskless portfolio) using shares and call options? Based on this conclusion, how does a single-step binomial tree option pricing model work? Use an example to demonstrate your answers. (Max.200 words, 10 marks) (b) How to replicate the payoff of a bond (riskless portfolio) using shares and call options? Based on this conclusion, how does a single-step binomial tree option pricing model work? Use an example to demonstrate your answers. (Max.200 words, 10 marks)