This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
A 54–year old obese patient with type 2 diabetes mellitus and a history of alcoholism probably should not receive metformin because it can increase the risk of: 
Select and explain. 
A. Disulfiram like reaction, B. Hypoglycemia, C. Lactic acidosis, D. Severe hepatic toxicity
C: Lactic acidosis
Answer: C: Lactic acidosis 
Explanation: None