A nurse is assessing a client who has diabetes mellitus type 2 and presents for a follow-up visit. Which of the following lab values is most indicative of inadequate control of their diabetes since their last primary care visit and requires further teaching?

C Random blood glucose level of 300 mg/dL (nl. <200 mg/dL) B 2-hour post-prandial blood glucose level of 122 mg/dL (nl. <120 mg/dL) D Fasting blood glucose level of 48 mg/dL (nl. 60-110 mg/dL) A HbA1c level of 7.5% (nl. 4.4-6.4%)