please explain the b part:)

A)The price of a European call that expires in six months and has a strike price of $28 is $2. The underlying stock price is $27, and a dividend of $0.50 is expected in two months and again in five months. The continuously compounded interest rate is 10%. What is the price of a European put option that expires in six months and has a strike price of $28? B) Explain the arbitrage opportunities in the earlier problem if the European put price is $3.25.