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
Absolute C/I of MRI is – a) Pacemakerb) Pregnancy at 1st trimesterc) Aneurysmal clipd) Phobia 
Select and explain. 
A. a, B. ac, C. ad, D. b
B: ac
Answer: B: ac 
Explanation: Cardiac pacemakers and ferromagnetic hemostatic clips in CNS (aneurysmal clip) are absolute contraindications for MRI.