<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 67-year-old man presents to his physician with increased thirst and polyuria for the past 4 months. Patient also notes a decrease in his vision for the past 6 months and tingling in his feet. The medical history is significant for a chronic pyelonephritis and stage 2 chronic kidney disease. The current medications include losartan and atorvastatin. He reports a daily alcohol intake of 3 glasses of whiskey. The blood pressure is 14090 mm Hg and the heart rate is 63min. The BMI is 35.4 kgm2. On physical examination, there is 2 pitting edema of the lower legs and face. The pulmonary, cardiac, and abdominal examinations are within normal limits. There is no costovertebral angle tenderness noted. Ophthalmoscopy shows numerous microaneurysms and retinal hemorrhages concentrated in the fundus. The neurological examination reveals a symmetric decrease in vibration and 2 point discrimination in the patients feet and legs extending up to the lower third of the calves. The ankle-deep tendon reflexes are decreased bilaterally. The laboratory test results are as follows:Serum glucose fasting 140 mgdLHbA1c 8.5BUN 27 mgdLSerum creatinine 1.3 mgdLeGFR 55 mLminThe patient is prescribed the first-line drug recommended for his condition. Which of the following side effect is associated with this drug?? A: Iron deficiency anemia, B: Hypoglycemia, C: Lactic acidosis, D: Infections, E: Hyperkalemia,  <response>: Based on the information provided in the question stem, this patient likely has diabetes mellitus type 2 with complications including diabetic retinopathy and diabetic neuropathy. The lab values indicate uncontrolled diabetes with an elevated HbA1c. The patient also has chronic kidney disease stage 3. The first-line drug treatment for type 2 diabetes is metformin. A potential side effect of metformin is lactic acidosis, especially in patients with kidney dysfunction. C: Lactic acidosis 