Explain what is meant by the delta of a stock option? What is the value of the delta for each step? Then, get the option value by using the delta-hedged portfolio. Finally, get the European put with the same strike and time to expiry by using Put-Call parity and, based on this stock, consider an American put option with the strike price is $42, the risk-free rate, the time to maturity, and time steps keep the same, what is the premium of this option.