Final answer:
An A1C blood test value of 6.5% or higher confirms a diagnosis of type 2 diabetes. Given the choices, options c (8%) and d (10%) are both indicative of diabetes.
Step-by-step explanation:
When diagnosing type 2 diabetes, the hemoglobin A1c test is critical as it measures the percentage of hemoglobin with glucose molecules attached. The A1C blood test value that confirms a diagnosis of type 2 diabetes is one that is 6.5% or higher. Specifically, for the choices provided in the question, an A1C value of 8% (option c) or 10% (option d) would indicate a diagnosis of diabetes. A level above 9% indicates poor control of diabetes, while a level above 12% indicates very poor control. Diabetic patients should aim to keep their A1C levels close to 7% to reduce the likelihood of complications.