The CDC measure tracks which of the following metrics?

The Centers for Disease Control and Prevention (CDC) measure primarily focuses on comprehensive metrics related to diabetes management, which includes A1C testing, retinal exams to assess eye health, nephropathy attention to monitor kidney function, and blood pressure (BP) control. These components are critical indicators of how well individuals with diabetes are managing their condition and receiving necessary preventive and monitoring services.

Monitoring A1C levels helps to determine blood sugar control over time, while retinal exams are essential for preventing vision loss due to diabetes-related complications. Nephropathy attention is important for recognizing and managing kidney issues, and maintaining proper blood pressure is crucial in reducing cardiovascular risks associated with diabetes.

The other options, while related to health metrics, do not align with the specific focus of the CDC measure as comprehensively as option C does. Emergency visit frequency addresses a different area of healthcare utilization, the percentage of members who received a flu shot pertains to vaccination rates, and the number of prescriptions filled for hypertension falls outside the specific diabetes management indicators tracked by the CDC measure. Thus, the focus on these four diabetes-related metrics makes option C the most relevant choice.