suppose you are attempting to value a 1-year expiration option on a stock with volatility (i.e., annualized standard deviation) of 0.48. a. 1 period of 1 year. b. 4 subperiods, each 3 months. c. 12 subperiods, each 1 month. What would be the appropriate values for u and d if your binomial model is set up using: (Do not round intermediate calculations Round your answers to 4 decimal places.) Subperiods At T a. b. . 1/4 0.25 1/12 0.0833 4 12