This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mood disorders, Subject name: Psychiatry
[{'content': 'A 17-year-old boy is diagnosed with schizophrenia. What is the risk that one of his siblings will develop the disease? \nSelect and explain. \nA. 2%, B. 5%, C. 9%, D. 20%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The risk of developing schizophrenia in first degree relatives of schizophrenic patients is elevated compared to the risk of the general population (0.9%). Parents of schizophrenic patients have a lifetime prevalence of 11%, and siblings have a prevalence of 9%. Identical twins have a 50% chance of suffering from schizophrenia if their sibling has it. Children of schizophrenics have a lifetime prevalence of 12.8%. Reference: Kaplon and sadock, 11 th edition, synopsis of psychiatry, 11 th edition, pg no. 310', 'role': 'assistant'}]