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: Radiology
[{'content': 'Absolute C/I of MRI is – a) Pacemakerb) Pregnancy at 1st trimesterc) Aneurysmal clipd) Phobia \nSelect and explain. \nA. a, B. ac, C. ad, D. b', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cardiac pacemakers and ferromagnetic hemostatic clips in CNS (aneurysmal clip) are absolute contraindications for MRI.', 'role': 'assistant'}]