Risk adjustment is used to make cost and efficiency comparisons fair by accounting for differences in patient severity and expected resource needs. In outpatient CDI, accurate documentation and coding of chronic and acute conditions (especially risk-adjusting diagnoses such as HCC-relevant conditions) directly influence the risk profile assigned to a patient population. That risk profile is then applied when evaluating utilization and cost measures-such as total cost of care, inpatient admissions, ED use, and other resource consumption-so that providers or groups caring for more complex patients are not inappropriately labeled as inefficient simply because their patients require more services. This aligns with option B: risk adjustment is applied to resource utilization measures. Option A is incorrect because E&M levels are a professional billing construct and are not the basis for risk score calculation. Option C is incorrect because physician time may affect E&M selection under certain rules, but it is not the mechanism for risk adjustment in cost efficiency analytics. Option D is incorrect because procedures/interventions describe services rendered, not the adjustment methodology itself.