This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'Kilnefelter no of chromosomes \nSelect and explain. \nA. 47, B. 46, C. 45, D. 44', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Klinefelter syndrome is best defined as male hypogonadism that develops when there are at least two X chromosomes and one or more Y chromosomes. Most affected patients have a 47,XXY karyotype. This karyotype results from nondisjunction of sex chromosomes during meiosis. The extra X chromosome may be of either maternal or paternal origin. (Robbins Basic Pathology, 9 th edition. page : 239)', 'role': 'assistant'}]