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 muscle is responsible for facial expression during smiling? 
Select and explain. 
A. Zygomaticus major, B. Levator labii superioris, C. Levator anguli oris, D. Procerus
A: Zygomaticus major
Answer: A: Zygomaticus major 
Explanation: None