Consider a European call option for a stock with current stock price S = 50, and with parameters r = 0.05, = 0, = 0.2, with time to expiration T being 3 months. The strike price is K. (a) Write down the formula for the Delta () of this option, using symbols but no numbers, except that you must use the assumption that = 0. Do not use the abbreviations d1 and d2 but write down in full what those expressions should be here. It suffices to give the answer. (b) (Determine the numerical value of K such that = 0.5. Use two decimals in your answer. Use a sufficient number of decimals in intermediate calculations so that the two decimals in the final answer are certainly correct. Show the details of your work.