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: Biochemistry
[{'content': 'Which of the following condition shows an increase in serum level of Creatinine Kinase 1 (CK 1)? \nSelect and explain. \nA. Myocardial ischemia, B. Brain ischemia, C. Kidney damage, D. Electrical cardioversion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: CK-1 or CK-BB is found primarily in brain tissue. Hence it is increased in brain ischemia. Ref: Clinical Biochemistry By Jiro J. Kaneko, John W. Harvey, Michael Bruss, 1997, Page 317', 'role': 'assistant'}]