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': 'In a case of intrauterine growth retardation, the most dependable method of determining fetal well being is : \nSelect and explain. \nA. Ultrasonic fetal cephalometry, B. Contraction stress test (oxytocin challenge test), C. Amniotic fluid triglyceride, D. Uteroplacental blood flow', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Contraction stress test (oxytocin challenge test)', 'role': 'assistant'}]