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': 'Which of the following has highest relative risk for placental abruption \nSelect and explain. \nA. Chorioamnionitis, B. Thrombophilia, C. Prior abruption, D. Preterm rupture of membrane', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Relative Risk for placental abruption is seen with prior abruption > Thrombophilia > Chorioamnionitis > PROM.', 'role': 'assistant'}]