The price of Alexion stock is $62 per share. The riskless interest rate for continuous compounding is 2% and the stocks volatility is 25%. Alexion stock does not pay dividends. (a) A put option on Alexion stock expires in six months, has a strike price equal to $65 per share, and is European exercise style. Using a binomial tree with two time steps, what is the price per share of the put option? Use replication to answer this question.