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': 'Spontaneous abortion in 1st trimester is caused by:a) Trisomy 21b) Monosomy c) Traumad) Rh-incompatibility \nSelect and explain. \nA. ab, B. bc, C. acd, D. abc', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Common causes of abortion', 'role': 'assistant'}]