A merchant's position in cash is -100 tons of corn, the variance of the forward price is 0.000749 and the covariance of the changes of the forward price with the changes of prices in case is 0.000524. If each future contract refers to 10 tons, how many future contracts will the merchant buy? Solve and choose one of the following:

a. 6

b. 7

c. 8

d.9