question: Q:A 72-year-old woman is brought to the emergency department 4 hours after the sudden onset of shortness of breath and dizziness. Her blood pressure is 88/56 mm Hg. Examination shows crackles at both lung bases and an S3 gallop. The extremities are cold to the touch. Serum studies show a urea nitrogen concentration of 15 mg/dL, a creatinine concentration of 1.0 mg/dL, and a lactic acid concentration of 6.4 mmol/L (N < 2). Arterial blood gas analysis on room air shows:
  pH 7.27
  pCO2 36 mm Hg
  HCO3- 15 mEq/L
  An ECG shows ST-segment elevation in the precordial leads. Which of the following is the most likely explanation for this patient's laboratory changes?"? 
  {'A': 'Catecholamine stimulation of glycolysis', 'B': 'Decreased reabsorption of HCO3-', 'C': 'Increased activity of HMG-CoA lyase', 'D': 'Defective mitochondrial oxygen utilization', 'E': 'Accumulation of NADH'},