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': 'Investigation contraindicated in antenatal expectant mother is : \nSelect and explain. \nA. X-rays, B. Ultrasound, C. Urine examination, D. Blood examination', 'role': 'user'}, {'content': 'Answer: A \nExplanation: X-rays', 'role': 'assistant'}]