This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition & Digestion, Subject name: Biochemistry
Toxicity of ethanol is due to: 
Select and explain. 
A. Increased NADH/NAD+ ratio, B. Decreased lactate/pyruvate ratio, C. Inhibition of gluconeogenesis, D. Stimulation of fatty acid oxidation
A: Increased NADH/NAD+ ratio
Answer: A: Increased NADH/NAD+ ratio 
Explanation: Ans. A. Increased NADH/NAD+ ratioHigh concentration of NADH leads to high NADH/NAD+ ratio. This is the basic cause of all metabolic alteration in alcoholism.