Final answer:
The nurse in the clinic should look for decreased cholesterol levels in the lab findings of a patient with type 2 diabetes mellitus to determine if their plan of care is effective.
Step-by-step explanation:
The nurse in the clinic is reviewing the lab findings of a patient with type 2 diabetes mellitus (DM). To determine if the patient's plan of care is effective, the nurse should look for specific lab findings. In this case, the finding that indicates the patient's plan of care is effective would be decreased cholesterol levels (option c).
High cholesterol levels are commonly seen in patients with diabetes, so a decrease in cholesterol levels would indicate that the patient's plan of care, including medication and a healthy lifestyle, is effectively managing their diabetes and its associated risk factors. Elevated HbA1c levels (option b), increased fasting blood glucose levels (option a), and higher blood pressure readings (option d) would indicate that the patient's diabetes is not well controlled and their plan of care may need adjustment.