You have the option to open a store today at a cost of 30, which would generate a present value of profits of 50. You can also delay opening the store for a +1 years. The cost would then rise to 50. The store's profits each year have a volatility of 40% and the risk-free rate is 4%. a. Using the Black and Scholes formula, what is the value of delaying the store opening? b. Should you invest today or delay? (Fill in "invest" or "delay")