Use the equation for the question(s) below. Consider the following linear regression model: (R, - )= a + b/RMK-7)+, The b, in the regression: O A. measures the diversifiable risk in returns. O B. measures the deviation from the best fitting line and is zero on average. O c. measures the sensitivity of the security to market risk. OD. measures the historical performance of the security relative to the expected return predicted by the SML