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: Dental
Moro's reflex is initiated by: 
Select and explain. 
A. The sudden movement of the neck., B. Sudden noise., C. Both., D. None.
A: The sudden movement of the neck.
Answer: A: The sudden movement of the neck. 
Explanation: None