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: Pediatrics
The following is usually the first sign of puberty in girls – 
Select and explain. 
A. Onset of menstruation, B. Appearance of pubic hair, C. Change in voice, D. Increase in breast size
D: Increase in breast size
Answer: D: Increase in breast size 
Explanation: None