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: Gynaecology & Obstetrics
[{'content': 'IUGR is caused by all except : \nSelect and explain. \nA. Rh incompatibility, B. Smoking, C. DM, D. CRF', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Rh incompatibility', 'role': 'assistant'}]