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': 'Trial of labour is contraindicated in all of the following except : \nSelect and explain. \nA. Primigravida, B. Hea disease, C. Cesarean section, D. PIH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Primigravida', 'role': 'assistant'}]