The price of Mancell stock, which pays no dividends, is $83 and the strike price of a 9-month European call option on the stock is $75. The risk-free rate is 5%. If the European call option price is $4.5 and Mancell stock price is above $75 at option expiration, what should be the greatest possible profit per share of option if actions are taken to use the arbitrage opportunity (Note: the value at expiration, not in present value terms)? Do not round intermediate calculations.