This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
All are ADRs of metformin except 
Select and explain. 
A. Diarrhoea, B. Wt gain, C. Nausea, D. Lactic acidosis
B: Wt gain
Answer: B: Wt gain 
Explanation: Metformin produces mild weight loss as it causes insulin sensitization and increases glucose uptake into skeletal muscles.Hence considered as drug of choice for patients who are obese and with DM. Ref: KD Tripathi 8th ed.