An investment center is evaluated not only on revenues and costs but also on how effectively it uses invested capital. Residual income is appropriate because it measures profit after deducting a required return on the investment base. This makes it suitable for assessing whether management generated returns above the organization’s minimum required rate. Cost centers are evaluated mainly on cost control, revenue centers on revenue generation, and profit centers on revenues minus expenses; none of these centers is directly responsible for invested capital. Flexible budgets and variance analysis can apply to many responsibility centers. Contribution margin reporting is useful for segment profitability but does not fully evaluate investment use. Therefore, residual income is uniquely suited to investment center evaluation, making Option D correct.