As read from left to right, the three variables in the equation R= ER) U indicate?

average return, expected return, and unexpected return. required return, expected return, and unbiased return. actual return, expected return, and unexpected retum. required return, expected return, and unbiased risk. required return, expected return, and unsystematic risk. average return, expected return, and unexpected return. required return, expected return, and unbiased return. actual return, expected return, and unexpected retum. required return, expected return, and unbiased risk. required return, expected return, and unsystematic risk