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: Gynaecology & Obstetrics
[{'content': 'Precocious puberty is defined as all of following except \nSelect and explain. \nA. Onset of menstruation before age of 10 years., B. Appearance of breast budding before age of 8 years in females., C. Menstruation before age of 8 years., D. Puberty occuring before 9 years in male.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Precocious puberty is menstruation before age of 10 years.', 'role': 'assistant'}]