A stock is traded at $50 a share, and there will be no dividend on the stock in 6 months. The 6-month European calls and puts on the stock with same strike price of $45 are traded at $8 and $2, respectively. The six-month risk-free rate is 5% with continuous compounding. Is there an arbitrage opportunity? If yes, construct an arbitrage portfolio and clearly explain how arbitrage profits are created. If no, why?