Please, quickly, I am taking the exam

A company has a $10 million portfolio with a beta of 1.5. Suppose that the standard deviation of semi-annual changes in the prices of a commodity is S0.72, the standard deviation of semi- annual changes in a futures price on the commodity is $0.81, and the coefficient of correlation between the two changes is 0.9. What is the optimal hedge ratio for a six-month contract? 0.8 0.9 O 1.2 0.642