The so-called "box spread" consists of four options: long E_1 call, short E_1 put, short E_2 call and a long E_2 put. 1. Calculate the payoff from a box spread at expiration, in terms of E_1 and E_2 2. Use put-call parity to calculate the price of the box spread at time tau = T-t before expiration, if the risk-free rate is r = 0. You do not need to know the prices of the individual options to price the box spread! 3. Give an explanation for your answer from the "no-arbitrage" point of view. 4. Profits from option trading are often taxed at a reduced rate (because the investor undertakes risk), when compared to tax rate on wage or (risk-free) interest earnings. Why do you think the IRS takes a dim view of using box spreads