A portfolio consists of a number of European call contracts, all on the same asset and with the same expiration. The strike prices for these calls are 3, 6, and 9. Draw the payoff diagram for this portfolio below, and on the next page work out how many calls of each type you must hold to make the portfolio, given that the payoff for the portfolio at various prices is given as follows. You may indicate that a call of a given strike has been written (i.e. the portfolio contains a short position in that call contract) by stating that the portfolio contains a negative number of contracts at the given strike. Price Payoff Calls held 0 0 3 0 6 6 9 9 12 6