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
Startle and Grasp Palmar reflex is initiated by: 
Select and explain. 
A. The sudden movement of the neck., B. Sudden noise or loud sound., C. Both., D. None.
B: Sudden noise or loud sound.
Answer: B: Sudden noise or loud sound. 
Explanation: None