Suppose that the standard deviation of monthly changes in the spot price of commodity A is $6.86. The standard deviation of monthly changes in the futures price for a contract on commodity B (which is similar to commodity A) is $8.32. The correlation between the changes in the futures price and the spot price of the commodity is 0.45. What hedge ratio should be used when hedging a one-month exposure to the price of commodity A? a. 1.21 b. 0.82 c. 0.55 d. 0.37