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: Physiology
[{'content': 'Voluntary stage of deglutition is: \nSelect and explain. \nA. Stage 1, B. Stage 2, C. Stage 3, D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Stage 1 is the oral phase and it is the voluntary stage of deglutition.', 'role': 'assistant'}]