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': 'McDonald stitch is applied in the following conditions except : \nSelect and explain. \nA. Incompetent os, B. Septate uterus, C. Placenta pre, D. Bad obstetrical history', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Placenta pre', 'role': 'assistant'}]