Consider the Regression Equation: R_it - R_ft = A_i

Consider the regression equation: r_it - r_ft = a_i + b_i(r_mt - r_ft) + e_it
Where:
R_it = return on stock i in month t
R_ft = the monthly risk-free rate of return in month t
R_mt = the return on the market portfolio proxy in month t
This regression equation is used to estimate

A) the security characteristic line.
B) benchmark error.
C) the capital market line.
D) All of the options
E) None of the options