Choice "A" is correct. Residual income is the segment margin of an investment center after deducting the imputed interest (hurdle rate) on the assets used by the investment center.
Choice "c" is incorrect. Return on investment is the ratio of income earned to the investment.
Choice "b" is incorrect. Operating income is not well defined, but is generally the income from operations for the entire organization, not a segment.
Choice "d" is incorrect. Return on assets is the ratio of income produced to assets employed (not the amount invested).
