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: Anatomy
Which of the following attains adult size before birth - 
Select and explain. 
A. Ear ossicles, B. Maxilla, C. Mastoid, D. Parietal bone
A: Ear ossicles
Answer: A: Ear ossicles 
Explanation: None