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
In precocious females, menstruation occurs : 
Select and explain. 
A. After 13 years of age, B. At 13 years of age, C. Less than 10 years of age, D. Below 12 years of age
C: Less than 10 years of age
Answer: C: Less than 10 years of age 
Explanation: Less than 10 years of age